If the average of 5 numbers is 20, and 4 of the numbers are 15, 25, 20, and 18, what is the fifth number?
Q1. If the average of 5 numbers is 20, and 4 of the numbers are 15, 25, 20, and 18, what is the fifth number?
Answer: 22
Explanation: The sum of the 5 numbers = 5 * 20 = 100. The sum of the 4 given numbers = 15 + 25 + 20 + 18 = 78. So, the fifth number = 100 - 78 = 22.