Question

The average age of 12 boys is 15 years if the average of first 2 boys is 20 years. Find the average age of last10 boys?​

Answer 1

Answer:

14

Step-by-step explanation:

The Average of 12 boys = 15 years

Sum Of the Age = 12×15=180

The Average of first 2 boys = 20 years

Sum of the Age = 2×20 years=40

Total age Of Boys = 180-40=140

Average of 10 Boys = 140/10 = 14 years

THUS, THE AVERAGE OF LAST 10 BOYS WILL BE 14 YEARS

Answer 2

Step-by-step explanation:

Let x be the sum of ages of all the boys.

Given average of all 12 boys is 15 years.

i.e x/12=15

then x = 180

Let y be the sum of ages of first 2 boys.

Given y/2=20

Then y=40

Now the average of last 10 boys is

(x-y)/10 = (180-40)÷10

= 140 ÷ 10

= 14 years.