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Manhattan Question Set # 8

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by richachampion » Sun Oct 09, 2016 6:00 pm
Can a batch of identical cookies be split evenly between Laurel and Jean without leftovers and without breaking a cookie?

(1) If the batch of cookies were split among Laurel, Jean and Marc, there would be one cookie left over.
(2) If Peter eats three of the cookies before they are split, there will be no leftovers when the cookies are split evenly between Laurel and Jean.

OA: B
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Source: — Problem Solving |

by [email protected] » Sun Oct 09, 2016 8:19 pm
Hi richachamption,

To start, this should be in the DS Forum. That having been said, this prompt can be solved by recognizing the Number Properties involved and by TESTing VALUES.

The question asks if a batch of cookies can be evenly split between two people. In real basic terms, it's asking if the total number of cookies is an EVEN NUMBER. This is a YES/NO question.

1) If the batch of cookies were split among Laurel, Jean and Marc, there would be one cookie left over.

This Fact tells us that the total number of cookies is 1 more than a multiple of 3.

IF... Total = 4, then the answer to the question is YES.
IF... Total = 7, then the answer to the question is NO.
Fact 1 is INSUFFICIENT

2) If Peter eats three of the cookies before they are split, there will be no leftovers when the cookies are split evenly between Laurel and Jean.

This Fact tells us that the total number of cookies is 3 more than a multiple of 2. Adding 3 to a multiple of 2 will ALWAYS lead to an ODD integer, so the answer to the question is ALWAYS NO.
Fact 2 is SUFFICIENT

Final Answer: B

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