Tuesday, February 7, 2017

Currency

Difficulty:


Problem:

Suppose there is a country whose currency is in only two denominations: $5 bills and $7 bills. What is the maximum amount that you cannot pay with these two types of bills?


Solution:

Monday, February 6, 2017

Apples

Difficulty:


Problem:

Al, Ben, Chris, and Don each took a number of apples from a bucket of 11 apples. Each person took at least one apple.

Al: Ben, did you take more apples than I did?
Ben: I don't know. Chris, did you take more apples than I did?
Chris: I don't know.

Having heard this conversation, Don was able to figure out exactly how many apples each person took. How many apples did Don take?


Solution: