Find X in a Cuboid: Volume 60 cm³ with Dimension (X+2)

Cuboid Volume Equations with Algebraic Dimensions

Look at the cuboid of the figure:

The volume of the cuboid is

60 cm³.

Work out the value of X.

333AAABBBDDDCCCEEEGGGFFFHHH5X+2

❤️ Continue Your Math Journey!

We have hundreds of course questions with personalized recommendations + Account 100% premium

Step-by-step video solution

Watch the teacher solve the problem with clear explanations
00:00 Find X
00:03 Use the formula for calculating box volume
00:06 height times length times width
00:12 Substitute appropriate values and solve for X
00:34 Isolate X
00:47 And this is the solution to the question

Step-by-step written solution

Follow each step carefully to understand the complete solution
1

Understand the problem

Look at the cuboid of the figure:

The volume of the cuboid is

60 cm³.

Work out the value of X.

333AAABBBDDDCCCEEEGGGFFFHHH5X+2

2

Step-by-step solution

To solve the problem of finding X X for a cuboid with a given volume, we proceed as follows:

  • Step 1: Identify the dimensions of the cuboid: 5cm 5 \, \text{cm} , X+2cm X+2 \, \text{cm} , and 3cm 3 \, \text{cm} .
  • Step 2: Recall the volume formula for a cuboid: V=l×w×h V = l \times w \times h .
  • Step 3: Substitute the known values into the volume equation: 5×(X+2)×3=60 5 \times (X+2) \times 3 = 60 .

Now, let's solve this equation step-by-step:

First, calculate the product involving X X :
5×3×(X+2)=60 5 \times 3 \times (X + 2) = 60 .

Simplify the left side:
15×(X+2)=60 15 \times (X + 2) = 60 .

Next, distribute the 15 on the left side:
15X+30=60 15X + 30 = 60 .

To isolate X X , subtract 30 from both sides:
15X=30 15X = 30 .

Finally, divide both sides by 15 to solve for X X :
X=2 X = 2 .

Therefore, the value of X X is 2 2 .

3

Final Answer

2 2

Key Points to Remember

Essential concepts to master this topic
  • Volume Formula: For cuboids multiply length × width × height
  • Technique: Substitute 5 × (X+2) × 3 = 60, then simplify to 15(X+2) = 60
  • Check: When X = 2, volume is 5 × 4 × 3 = 60 cm³ ✓

Common Mistakes

Avoid these frequent errors
  • Forgetting to distribute multiplication through algebraic expressions
    Don't write 15 × (X+2) = 15X + 2 instead of 15X + 30 = wrong answer! This ignores the distributive property and gives incorrect solutions. Always multiply the coefficient by every term inside parentheses.

Practice Quiz

Test your knowledge with interactive questions

Calculate the volume of the rectangular prism below using the data provided.

888333222

FAQ

Everything you need to know about this question

How do I know which dimensions to multiply?

+

For any cuboid, multiply all three dimensions together: length × width × height. The order doesn't matter - just make sure you use all three measurements!

What if I can't see all the dimensions clearly?

+

Look carefully at the diagram labels. In this problem, the dimensions are 5 (bottom edge), X+2 (side edge), and 3 (height). Each cuboid has exactly three different measurements.

Why do I need to solve for X instead of just calculating volume?

+

The volume is already given as 60 cm³! Your job is to work backwards - use the known volume and two known dimensions to find the unknown dimension X+2.

Can X be negative in this problem?

+

No! Since X+2 represents a length, it must be positive. If your algebra gives you X = -5, that would mean a dimension of -3 cm, which is impossible for a real object.

How do I check my answer is reasonable?

+

Substitute back: if X = 2, then dimensions are 5 × 4 × 3. Calculate: 5 × 4 × 3 = 60 ✓ This matches the given volume, so X = 2 is correct!

🌟 Unlock Your Math Potential

Get unlimited access to all 18 Cuboids questions, detailed video solutions, and personalized progress tracking.

📹

Unlimited Video Solutions

Step-by-step explanations for every problem

📊

Progress Analytics

Track your mastery across all topics

🚫

Ad-Free Learning

Focus on math without distractions

No credit card required • Cancel anytime

More Questions

Click on any question to see the complete solution with step-by-step explanations