The average of 42 numbers is 25 and that of other 28 numbers is 40. What is the average of all the numbers?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e 31.
Total numbers = 42 + 28 = 70
Sum of first 42 numbers = 42 × 25 = 1050
Sum of next 28 numbers = 28 × 40 = 1120
Total sum = 1050 + 1120 = 2170
Average of all 70 numbers = 2170 ÷ 70 = 31