The ratio of boys to girls initially in a college is 5 : 6. If 40 boys leave the college and 50 girls join the college, the ratio will become 8 : 11. Find the number of girls (initial) in the college.
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 720.
The ratio of boys to girls initially in a college = 5x : 6x
So, =
⇒ 11(5x - 40) = 8(6x + 50)
⇒ 55x - 48x = 400 + 440
⇒ x = 840/7 = 120
The initial number of girls in the college = 6x = 6 × 120 = 720