Question

The average weight of a group of 10 girls is 48kg.If 2 girls R and S replace P and Q then the new average is 47kg.​

Answer 1

Answer:

Number of boys = x (let)

Number of girls = y (let)

Therefore, 45×x+36×yx+y=42.25

=> 45x + 36y = 42.25x + 42.25y

=> 45x - 42.25x = 42.25y - 36y

=> 2.75x = 6.25y

=> xy=62.252.75=2511