Question

A woman reduces her weight in the ratio 7:5 . What does her weight become if originally it was 91 kg

Answer 1

Let the weight after reduction be x.
∴ 91/x = 7/5
⇒ x = 91/7 × 5 = 65
Her weight becomes 65 kg if originally it was 91 kg.

Answer 2

Let her present weight be y.

7:5 :: 91:y

So, 

91*5 = 7y

455    = 7y

  y       = 455/7

∴y      = 65