The average of five test scores is 20. If four scores are 15, 18, 22, and 25, what is the fifth score?
Q1. The average of five test scores is 20. If four scores are 15, 18, 22, and 25, what is the fifth score?
Answer: 20
Explanation: Five numbers with average 20 have a total of 100. The four given scores sum to 80, so the fifth score is 20.