When each of the children in a room was given the same number of

Similar question from GMAT Prep Focus https://gmatclub.com/forum/when-each-of ... 21605.html Hope it helps.­­­­­­

­Yes, sorry, this is from a GMAT Focus Practice exam.

 

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The fastest way is to test each answer:

A) 45 % 3 = 0 (remainder is 3 less)
B) 45 % 8 = 5 (remainder is 3 less)
C) 45 % 12 = 9 (remainder is 3 less)
D) 45 % 14 = 17 (remainder is 3 more) -> answer
E) 45 % 16 = 13 (remainder is 3 less)

When each of the children in a room was given the same number of crayons from a box containing 45 crayons, the number of crayons left in the box was 3 less than the number of children in the room. Which of the following could NOT have been the number of children in the room?

A. 3
B. 8
C. 12
D. 14
E. 16

Finding four that work may be easier than the one that doesn't!

3 children - You can tell that 45 crayons can be divided perfectly among 3 children, so it's possible to be left with 0 crayons.... which is 3 less than the number of children in this scenario. This works.

8 children - Finding your target could be helpful. What is 3 less than 8? It's 5. So we are basically checking to see whether there is a multiple of 8 that is equal to (45-5) = 40. 8 times 5 is 40 so this options works, too!

12 children - Use the same process. What is 3 less than 12? 9. What is 45-9? 36. Is 36 a multiple of 12? Yes! This works, too.

14 children - What is 3 less than 14? 11. What is 45-11? 34. Is 34 a multiple of 14? No.

16 children - What is 3 less than 16? 13. What is 45-13? 32. Is 32 a multiple of 16? Yes.

Once you get the "process" you could probably get through some of the options more quickly.

(D) is your answer.