The average age of five girls 11. The oldest among them is 15 years old. What is the average of the others?
20
15
10
none of these
Explanation:
Let `T` be the total age of 5 girls.
Then, T/5 = 11.
=> T = 55.
Given, Age of the Oldest girl = 15.
Then, Total age of other 4 girls will be 55-15=40.
So, Avg. of other 4 girls 40/4 = 10.