Average of 11 numbers is 45. Average of first 5 is 42 and last 5 is 46. Find the 6th number.
Show answer & explanation
Correct answer: A
Explanation
Average of 11 numbers = 45
Total sum of 11 numbers = 11 × 45 = 495
Average of the first 5 numbers = 42
Sum of the first 5 numbers = 5 × 42 = 210
Average of the last 5 numbers = 46
Sum of the last 5 numbers = 5 × 46 = 230
Sixth number = 495 − (210 + 230)
= 495 – 440 = 55