Question

In a certain primary school there are 60 boys of age 12 40 of age 13 ,50 of age 14 each,50 of age 15 each .the average age of the boys of the school is

Answer 1

Average

In school, number of boys of age twelve $=60$

Number of boys of age thirteen$=40$

Number of boys of age fourteen $=50$

Number of boys of age fifteen $=50$

Hence the average age of boys of the school will be sum of product of age and number of boys divided by total number of boys in school ,

$Average =\frac{[(60\times12)+(40\times13)+(50\times14)+(50\times15)]}{60+40+50+50}\\\\\implies Average=\frac{(720+520+700+750}{200} \\\\\implies Average= \frac{2690}{200}=13.45$

Hence the average age of boys of the school will be 13.45 years.