The average weight of boys in a class is 30 kg and the average weight of girls in the same class is 20 kg. If the average weight of the whole class is 23.25 kg, what could be the possible strength of boys and girls respectively in the same class?

A. 14 and 26

B. 13 and 27

C. 17 and 17

D. None of these

Answer: Option B

Solution(By Examveda Team)

Let the number of boys and girls in the class are x and y.
According to given information,
⇒ 30x + 20y = 23.25 (x + y)
⇒ 30x + 20 y = 23.25x + 23.25y
⇒ 30x - 23.25x = 23.25y - 20y
⇒ 6.75x = 3.25y
⇒ $$\frac{x}{y}$$ = $$\frac{3.25}{6.75}$$
⇒ $$\frac{x}{y}$$ = $$\frac{13}{27}$$
Hence, possible number of boys and girls 13 and 27 respectively.