Question

There are 140 boxes of cupcakes. Each box has a minimum of 9 and maximum of 20 cupcakes. The least number of boxes that contain the same number of cupcakes will be ?

Answer 1

It's a pigeon hole principle question. Think about our like this: you have 12 different possible amounts of cupcakes. If you only had at most 10 of each of these possibilities, you could only have at most 12\*10=120 boxes of cupcakes, so the number of boxes with the same number of cupcakes must be higher.

Answer 2

7

Answer 3

129. There are 11 boxes with one of the following amounts of donuts: 9, 10, 11,12,13,14,15,16,17,18,19 (or 11 boxes with a unique qty of donuts), which means that there are 140-11=129 remaining boxes with matching donuts (20) therefore with 11 boxes with unique values then 129 have the same value.