The average of 9 numbers is 100. The average of the first 4 numbers is 65 and the average of the last 4 numbers is 40. What is the 5th number?
Total sum of 9 numbers = 9 × 100 = 900 Sum of first 4 numbers = 4 × 65 = 260 Sum of last 4 numbers = 4 × 40 = 160 According to question, => 900 – (260 + 160) = 480
