The Wednesday Morning Math Challenge: Week 6

Welcome to Week 6 of the Wednesday Morning Math Challenge. You can find solutions to the Week 5 puzzles here, along with — more importantly — discussions of some ways to approach them. Remember that the real goal here is to think creatively.

This week, we have three puzzles involving time.

1. It takes five pigs five minutes to eat five kilograms of meat. How long does it take 99 pigs to eat 99 kilograms of meat?

2. In a given day, how many times do the hour and minute hands on a clock overlap?

3.You are given two pieces of string and a lighter. If you light one end of one of the strings, it will take an hour to burn through the whole string. However, neither of the strings burn uniformly and they are not identical. How can you determine when 45 minutes has passed?