Correct Answer - Option 2 : 1500
Given:
The ratio of number of boys and girls = 5 : 7
In the next session, 250 boys and 450 girls joined
Calculation:
Let the ratio of boys and girls be 5x : 7x
According to the question
\(\dfrac{5x \ + \ 250}{7x \ + \ 450} = \dfrac{2}{3}\)
⇒ 15x + 750 = 14x + 900
⇒ x = 150
The number of girls now
7 × 150 + 450 = 1500
∴ The number of girls now is 1500.