If the average of ten numbers is 50 and the average of the first six numbers is 45, what is the average of the last four numbers?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 57.5.
Total sum of 10 numbers = 50 × 10 = 500
Sum of first 6 numbers = 6 × 45 = 270
Sum of last 4 numbers = 500 – 270 = 230
Average of last 4 numbers = 230/4 = 57.5