Practice!

Sample Problem

Benson and Tim take an average of 5.4 minutes to complete a 500-yard swim. Benson, Tim and Jack average 6 minutes for the 500-yard swim. What was Jack's average time for the swim?

  minutes

Solution

The total time for Benson and Tim: 5.4 × 2 = 10.8

The total time for Benson, Tim and Jack: 6 × 3 = 18

Thus, Jack’s time: 18 – 10.8 = 7.2