The average of five positive numbers is 56. If the first number is three-fourth of the sum of the last four numbers, then the average of the last four numbers is:
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 40
Let the five numbers are a, b, c, d and e.
a + b + c + d + e = 56 × 5
a + b + c + d + e = 280.................(1)
According to the question,
a = 3/4(b + c + d + e)..................(2)
3/4(b + c + d + e) + b + c + d + e = 280
7/4(b + c + d + e) = 280
( b + c + d + e) = 160
Average of these four number = 160/4 = 40.