Examples with solutions for Quantity, percentage, percentage value: Worded problems

Exercise #1

The price of the movie ticket rose from 40 to 45 pesos. By what percentage did the price increase?

Step-by-Step Solution

In order to answer the question we must first understand how much the ticket costs:

45-40=5

That is, the price of the ticket increased by 5$.

Now we need to determine what the percentage value of the 5 pesos increase is. In order to determine this we will divide the increase by the original price and multiply it by 100 to convert it into a percentage.

5/40 * 100

We start by converting the 100 into fraction form.

5/40 * 100/1

When there is a multiplication of fractions, we can multiply numerator by numerator and denominator by denominator.

5*100 / 40*1

500 / 40

Thus we simplify as follows:

50/4

Lastly we convert the fraction into its complete form.

50/4 = 12.5

Answer

12.5%

Exercise #2

A toy costing $40 is reduced by 20%

What is the new price following the discount?

Video Solution

Step-by-Step Solution

408=32 40-8=32

In order to determine percentages, we must make use of the two pieces of information in our possession: the total amount (40)andthediscount(2040) and the discount (20%).</p><p>This information can be inserted into the following formula:</p><p><span class="katex">\( \frac{Price\times\text{Percentage}}{100}

Which allows us to find the percentage of something.

We insert the given information:

40×20100= 40\times\frac{20}{100}=

800100= \frac{800}{100}=

8 8

We then discover that the value of the discount is 8.

But we are not finished yet!

We need to subtract the discount from the original amount in order to determine the sale price:
\( 40-8=32

Answer

32

Exercise #3

George has $3000. He wants to give 20% of it to William and 25% to Alexander. How much money will William receive?

Video Solution

Step-by-Step Solution

To solve the problem, we will calculate the amount that William will receive by following these steps:

  • Step 1: Convert the percentage to a decimal by dividing by 100. Since William's portion is 20%, convert it to decimal: 0.20 0.20 .

  • Step 2: Multiply the total amount by this decimal to find William's share: 0.20×3000 0.20 \times 3000 .

Now, carrying out the multiplication:
0.20×3000=600 0.20 \times 3000 = 600
Thus, William will receive \600\).

Therefore, the solution to the problem is 600 600 , which corresponds to choice 3 in the options provided.

Answer

600

Exercise #4

In a box there are 28 balls, 14 \frac{1}{4} of which are orange.

How many orange balls are there in the box in total?

Video Solution

Step-by-Step Solution

To solve this problem, we'll determine the number of orange balls by calculating the fraction of the total number of balls:

  • Step 1: Identify the total number of balls, 28 28 .
  • Step 2: Note the fraction representing the orange balls, 14 \frac{1}{4} .
  • Step 3: Apply the formula to find the number of orange balls:
    Number of orange balls =28×14 = 28 \times \frac{1}{4}

Now, let's perform the calculation:
28×14=28÷4=7 28 \times \frac{1}{4} = 28 \div 4 = 7

Therefore, the number of orange balls in the box is 7 7 .

Answer

7

Exercise #5

A jar contains 500 grams of jam. 25% of the weight is water, while the rest is strawberry. How many cubic centimeters of water are there in the jar?

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Calculate the weight of water.
  • Step 2: Convert this weight into volume (cubic centimeters).

Let's work through each step:

Step 1: Calculate the weight of water.
The total weight of the jar's contents is 500 grams. Since 25% of this weight is water, we calculate the weight of water as follows:

Weight of water=25%×500 grams \text{Weight of water} = 25\% \times 500 \text{ grams}

Weight of water=0.25×500=125 grams \text{Weight of water} = 0.25 \times 500 = 125 \text{ grams}

Step 2: Convert the weight into volume.
Given that the density of water is 1 gram per cubic centimeter, the volume of water can be directly found as follows:

Volume of water (in cm3)=Weight of water (in grams) \text{Volume of water (in cm}^3\text{)} = \text{Weight of water (in grams)}

Volume of water=125 cm3 \text{Volume of water} = 125 \text{ cm}^3

Therefore, the solution to the problem is 125 cubic centimeters of water.

Answer

125

Exercise #6

The original price of a coat is $200. If the coat is discounted by 20%:
How much does the price of the coat decrease by after the discount?

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given information
  • Step 2: Apply the appropriate formula
  • Step 3: Perform the necessary calculations

Let's go through each step:
Step 1: The original price of the coat is 200, and the discount percentage is 20%.

Step 2: We use the formula to calculate the discount amount:
\(\text{Discount Amount} = \text{Original Price} \times \left(\frac{\text{Discount Percentage}}{100}\right)

Step 3: Substitute the given values into the formula:
Discount Amount=200×(20100)=200×0.2=40\text{Discount Amount} = 200 \times \left(\frac{20}{100}\right) = 200 \times 0.2 = 40

Therefore, the price of the coat decreases by \40 \) after the discount.

Answer

40

Exercise #7

The weight of a cake is 2 kg, 10% of which is chocolate.

How many kg of chocolate are there in the cake?

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given information
  • Step 2: Apply the appropriate formula
  • Step 3: Perform the necessary calculations

Now, let's work through each step:


Step 1: The total weight of the cake is 2kg2\, \text{kg}, and chocolate makes up 10%10\% of this.


Step 2: To find the weight of the chocolate, we use the formula: Chocolate weight=(Percentage100)×Total weight of the cake \text{Chocolate weight} = \left( \frac{\text{Percentage}}{100} \right) \times \text{Total weight of the cake} This is: Chocolate weight=(10100)×2 \text{Chocolate weight} = \left( \frac{10}{100} \right) \times 2

Step 3: Performing the calculation: =0.1×2=0.2 = 0.1 \times 2 = 0.2

Therefore, the weight of the chocolate in the cake is 0.2kg0.2\, \text{kg}.

Checking the multiple-choice options, the correct choice is the one with 0.20.2, which corresponds to choice 44.

Answer

0.2

Exercise #8

There are 32 children in a class, 50% of whom are boys.

How many boys are there in the class in total?

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the given information.
  • Step 2: Apply the appropriate percentage calculation.
  • Step 3: Perform the mathematical operations.

Now, let's work through each step:

Step 1: The total number of children in the class is 32, and 50% of these children are boys.

Step 2: We need to find 50% of 32. This can be calculated by using the formula for percentage:

Number of boys=(50100)×32\text{Number of boys} = \left(\frac{50}{100}\right) \times 32

Step 3: Simplify the calculation:

50100=0.5\frac{50}{100} = 0.5

Thus, the calculation becomes:

0.5×32=160.5 \times 32 = 16

Therefore, the solution to the problem is that there are 16 boys in the class.

Answer

16

Exercise #9

A pool contains 1000 liters of water. After three days, 35% of the total water remains. How many liters are left in the pool after three days?

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the percentage of the initial amount needed.
  • Step 2: Calculate the corresponding amount of water using the percentage formula.

Now, let's work through each step:

Step 1: We need to find 35% of the initial 1000 liters.

Step 2: Using the formula to find a percentage of a number, we have:

Amount of water remaining=(35100)×1000 \text{Amount of water remaining} = \left(\frac{35}{100}\right) \times 1000

Calculating this gives:

=0.35×1000 = 0.35 \times 1000

= 350

Therefore, the number of liters left in the pool after three days is 350 350 liters.

Answer

350

Exercise #10

A group of 140 adults and children went on a trip:

If 60% of those on the trip were adults, how many adults were there in total?

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Identify the total number of people, which is 140.
  • Step 2: Recognize that 60% of these are adults.
  • Step 3: Convert 60% into a decimal fraction: 60100=0.6\frac{60}{100} = 0.6.
  • Step 4: Multiply the total number of people by the decimal fraction: 0.6×140 0.6 \times 140 .

Now, let's perform the calculation:
Step 1: We have 140 people in total.
Step 2: 60% of these are adults.
Step 3: Converting 60% to a decimal gives us 0.6.
Step 4: Multiply 0.6 by 140:

0.6×140=84 0.6 \times 140 = 84

Therefore, the number of adults in the group is 84.

Answer

84

Exercise #11

If there are 18 balls in a box of which 23 \frac{2}{3} are white:

How many white balls are there in the box in total?

Video Solution

Step-by-Step Solution

To solve this problem, we will determine the number of white balls in the box using a fraction of the total number of balls.

We are given the total number of balls in the box as 18, and we know that 23 \frac{2}{3} of these balls are white. To find the number of white balls, we follow these steps:

  • Step 1: Identify the total quantity, which is 18 balls.
  • Step 2: Use the given fraction 23 \frac{2}{3} to find the number of white balls.
  • Step 3: Multiply the total number of balls by the fraction of white balls: 18×23 18 \times \frac{2}{3} .

Perform the calculation:

18×23=18×0.6667=12 18 \times \frac{2}{3} = 18 \times 0.6667 = 12

Alternatively, calculate directly using fractions:

18×23=18×23=363=12 18 \times \frac{2}{3} = \frac{18 \times 2}{3} = \frac{36}{3} = 12

Thus, the total number of white balls in the box is 12.

Therefore, the correct answer is choice 12.

Answer

12

Exercise #12

In a car's fuel tank there are 60 liters of fuel. On the first day 10% of the fuel is used and on the second day 15% of the fuel is used.

How many liters of fuel are used on the second day?

Step-by-Step Solution

To solve this problem, follow these steps:

  • Identify original fuel quantity and calculate daily usage based on percentage.

  • Determine the remaining fuel after the first day's usage.

  • Calculate the liters used on the second day based on remaining fuel.

Let's go through the solution step-by-step:
Step 1: Calculate 10% of 60 liters (fuel used on the first day).
Fuel used on first day=10100×60=6 liters\text{Fuel used on first day} = \frac{10}{100} \times 60 = 6 \text{ liters}

Step 2: Calculate remaining fuel after the first day:
Remaining fuel=606=54 liters\text{Remaining fuel} = 60 - 6 = 54 \text{ liters}

Step 3: Calculate 15% of the remaining fuel for usage on the second day:
Fuel used on second day=15100×54=8.1 liters\text{Fuel used on second day} = \frac{15}{100} \times 54 = 8.1 \text{ liters}

Therefore, the amount of fuel used on the second day is 8.1 liters.

Answer

8.1

Exercise #13

If 30% of the dolls in a toy shop are standard issue and the remaining 21 dolls are limited edition. How many dolls are there in the shop in total?

Step-by-Step Solution

To solve this problem, follow these steps:

  • Step 1: Define the total number of dolls in the toy shop as x x .
  • Step 2: Note that 30% of these dolls are standard issue, thus 0.30x 0.30x are standard issue dolls.
  • Step 3: Since 70% of the dolls are limited edition (as standard and limited edition must account for 100% of the shop's dolls), 0.70x 0.70x would be limited edition dolls.
  • Step 4: Set up the equation: 0.70x=21 0.70x = 21 , since we know the exact count of limited edition dolls is 21.
  • Step 5: Solve for x x by dividing both sides of the equation by 0.70:
\begin{align*} 0.70x &= 21 \\ x &= \frac{21}{0.70} \\ x &= 30 \end{align*}

Therefore, the total number of dolls in the shop is 30 30 .

Answer

30

Exercise #14

The price of a table is 150% greater than the price of a chair.
Determine the individual prices for a table and a chair separately.

Video Solution

Step-by-Step Solution

To solve this problem, let's follow these steps:

  • Step 1: Define the variables. Assume the price of a chair is C C dollars.

  • Step 2: Determine the price increase for the table. Since the table's price is 150% greater than the chair's, calculate 150% of C C , given by 1.5×C 1.5 \times C .

  • Step 3: Compute the table's price. The price T T of the table is the sum of the chair's price and the calculated increase: T=C+1.5×C T = C + 1.5 \times C .

  • Step 4: Simplify the expression. This results in T=2.5×C T = 2.5 \times C .

Now, substituting values from the given options (since T=2.5×C T = 2.5 \times C ) reveals the following key information:

For option 3, with Chair at 100\ \), assuming Chair's price to be C=100 C = 100 :
T=2.5×100=250 T = 2.5 \times 100 = 250 .

Verification shows a chair price of 100\ \) and table price of 250\ \) as per our calculations. This matches our established equation, confirming it as the correct choice where a chair costs 100\ \) and a table costs 250\ \).

Thus, the individual prices are C=100 dollars and T=250 dollars C = 100 \ \text{dollars and} \ T = 250 \ \text{dollars} , which aligns with option 3 in given choices.

Answer

Chair 100 andatable150 and a table 150

Exercise #15

During recess 15 \frac{1}{5} of the students play catch, 20% play soccer and the remaining 15 students watch a movie.

How many students are there in total?

Step-by-Step Solution

To solve this problem, we will find a common equation to account for all students:

  • Activity: Playing catch, Fraction: 15x\frac{1}{5}x
  • Activity: Playing soccer, Fraction: 20% of xx which is 15x\frac{1}{5}x
  • Activity: Watching a movie, Number: 1515 students

The total number of students involved is xx. Thus, the setup for the equation is:

15x+15x+15=x\frac{1}{5}x + \frac{1}{5}x + 15 = x

Simplify and solve for xx:

25x+15=x\frac{2}{5}x + 15 = x

Subtract 25x\frac{2}{5}x from both sides:

15=x25x15 = x - \frac{2}{5}x

15=35x15 = \frac{3}{5}x

To isolate xx, multiply both sides by 53\frac{5}{3}:

x=15×53x = 15 \times \frac{5}{3}

x=25x = 25

Therefore, the total number of students is 25 students.

Answer

25 students

Exercise #16

The price of a notebook is 30% higher than the price of a pen.

If together a notebook and a pen cost 18.4 $:
How much is the notebook and how much is the pen?

Video Solution

Step-by-Step Solution

To find the individual prices of the notebook and pen:

  • Define the price of the pen as x x .

  • The notebook price, therefore, will be \( 1.3x becauseitis30because it is 30% higher.</p></li><li><p>Form the equation based on the total cost:</p></li></ul><p>Equation:</p><p><span class="katex">\( x + 1.3x = 18.4

    Combine like terms to simplify:

    2.3x=18.4 2.3x = 18.4

    To find x x , divide both sides by 2.3:

    x=18.42.3 x = \frac{18.4}{2.3}

    Calculate x x :

    x=8 x = 8

    Thus, the price of the pen is 8. Now calculate the price of the notebook:

    \( 1.3x = 1.3 \times 8 = 10.4

    The price of the notebook is 10.4.</p><p>Therefore,thesolutiontotheproblemis:<strong>Notebook10.4.</p><p>Therefore, the solution to the problem is: <strong>Notebook 10.4, pen 8$.

Answer

Notebook 10.4 ,pen8, pen 8

Exercise #17

There are 180 students in total in the seventh grade.

If male students make up 40% of the student body:
How many female students are there in the seventh grade?

Step-by-Step Solution

To find the number of female students in the seventh grade, we first identify the number of male students and then subtract that from the total number of students.

Step 1: Calculate the number of male students.
Percentage of male students = 40% = 0.40
Total number of students = 180
Number of male students = 180 × 0.40
Number of male students = 72 72

Step 2: Calculate the number of female students.
Total number of students = 180
Number of female students = Total number of students - Number of male students
Number of female students = 180 - 72
Number of female students = 108 108

Answer

108 108

Exercise #18

A group of students and teachers go on a school trip, of which 180 are students.
25% of the group are from the eighth grade, 20% are from the ninth grade, 40% are from the seventh grade, and the rest of the group are teachers.

How many students from the seventh and eighth grades go on the trip?

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Calculate the number of eighth-grade students
  • Step 2: Calculate the number of seventh-grade students
  • Step 3: Sum the number of students from the seventh and eighth grades

Now, let's work through each step:
Step 1: The eighth-grade students make up 25% of the students. Therefore, the number of eighth-grade students is 180×25100=45 180 \times \frac{25}{100} = 45 students.

Step 2: The seventh-grade students make up 40% of the students. Therefore, the number of seventh-grade students is 180×40100=72 180 \times \frac{40}{100} = 72 students.

Step 3: Adding the number of students from the seventh and eighth grades gives us: 45+72=117 45 + 72 = 117 students.

Therefore, the number of students from the seventh and eighth grades that go on the trip is 117 students.

Answer

117 students

Exercise #19

In total there are 124 tables in a room. A number of tables were manufactured in Holland whilst the remaining tables were manufactured in China.

If 25% of the tables were manufactured in Holland determine how many tables were manufactured in China?

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Calculate the number of tables manufactured in Holland using the given percentage.
  • Step 2: Subtract that number from the total number of tables to find how many were manufactured in China.

Now, let's work through each step:
Step 1: The problem states that 25% of the tables were manufactured in Holland. We can calculate this quantity as follows:
Tables in Holland=25100×124=31\text{Tables in Holland} = \frac{25}{100} \times 124 = 31

Step 2: To find the number of tables manufactured in China, we subtract the number of tables manufactured in Holland from the total:

Tables in China=12431=93\text{Tables in China} = 124 - 31 = 93

Therefore, the number of tables manufactured in China is 93 93 .

Answer

93

Exercise #20

7000 $ was shared between three people.

The first person received 40% of the total, the second person received 15% of the total and the third person received the remainder.

How much money did they each receive?

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Determine how much the first person receives by calculating 40% of 7000.</li><li>Step2:Determinehowmuchthesecondpersonreceivesbycalculating157000.</li> <li>Step 2: Determine how much the second person receives by calculating 15% of 7000.
  • Step 3: Calculate the amount the third person receives by finding the remainder after the first two allocations.

Let's proceed with each step:
Step 1: Calculate 40% of 7000. The formula to use is:

\( \text{Amount} = \frac{40}{100} \times 7000 = 2800

Thus, the first person receives 2800</strong>.</p><p><strong>Step2:</strong>Calculate152800</strong>.</p> <p><strong>Step 2:</strong> Calculate 15% of 7000. Using the same formula:

Amount=15100×7000=1050 \text{Amount} = \frac{15}{100} \times 7000 = 1050

Therefore, the second person receives 1050.

Step 3: Calculate the remaining amount for the third person:

\( \text{Remainder} = 7000 - (2800 + 1050) = 3150

This means the third person receives 3150</strong>.</p><p>Toconfirm,thetotal3150</strong>.</p> <p>To confirm, the total 7000 is distributed correctly as 2800+1050+3150=70002800 + 1050 + 3150 = 7000.

Thus, the amount received by each person is:

  • The first person received 2800.</li><li>Thesecondpersonreceived2800.</li> <li>The second person received 1050.
  • The third person received $3150.

Therefore, the correct solution is choice #3.

Answer

The first person received 2800 dollars: the second person received 1050 dollars and the third person received 3150 dollars.