Average of 12 numbers is 60. If 12 is subtracted from the first five numbers and 10 is added in the next seven numbers, then what will be the new average?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 60.83.
Sum of the 12 numbers = 12 × 60 = 720
The total change for these five numbers will be:
⇒ 5 × (-12) = -60
The total change for these seven numbers will be:
⇒ 7 × 10 = 70
The new sum of the 12 numbers is the original sum plus the total changes:
New sum = 720 + (-60) + 70 = 720 - 60 + 70 = 730
New average = 730 / 12 = 60.83