Arrange 4, 2, 3, 1 to Form a Divisible by 4 Number

Question

Rearrange the following digits to that they form a number divisible by 4:

4, 2, 3 , and 1.

Video Solution

Step-by-Step Solution

To solve this problem, we will apply the divisibility rule for 4:

A number is divisible by 4 if the number formed by its last two digits is divisible by 4. Therefore, we need to consider pairs from the digits 1,2,3,1, 2, 3, and 44 that can form numbers divisible by 4. Let's list them:

  • 12: Not divisible by 4.
  • 21: Not divisible by 4.
  • 32: Divisible by 4 (32÷4=832 \div 4 = 8).
  • 42: Divisible by 4 (42÷4=10.542 \div 4 = 10.5 - Incorrect!).

From the list above, the only pair that forms a number divisible by 4 is 3232. By setting the last two digits as 3232, we use the remaining digits 11 and 44 as the preceding two digits to form the complete number.

Possible numbers using this order include x132x132, where xx is any combination of the remaining 1,41, 4.

Let's attempt to form a number:
Arrange 3,1,2,43, 1, 2, 4: 3131 and 2424, yielding 3124.
Verify if it matches our condition as laid in the answer choices.

Looking through our options, only 31243124 fits a number divisible by 4.

Thus, the number 3124 fulfills the condition of divisibility by 4.

Therefore, the solution to the problem is 3124 3124 .

Answer

3124