The average age of a set of 30 persons is 35. The average of 20 persons is 18. What will be the average of the remaining?
A57.5
B58
C69
D58.5
Answer:
C. 69
Read Explanation:
Total age of 30 persons = 30 x 35 = 1050
Total age of 20 persons = 20 x 18 = 360
The age of remaining = 1050 - 360 = 690
The average age of remaining 10 persons
= 690 ÷ 10
= 69
