Mrs Rane gives 0.025 part of her salary as pocket money to her son Vinod every month.Vinod spends0.8  part of his pocket money and saves the rest.If he saves Rs277.50 in three months ,how much does Mrs Rane earn?

Let us assume Mrs Rane earns Rs. A every month.

Vinod had saved Rs. 277.50 in 3 months

So the amount saved by Vinod in one month = 277.50 / 3 = Rs. 92.50.

The amount given by Mrs Rane every month to Vinod = 0.0.025 of A = 0.0.025A

The amount spend by Vinod every month = 0.8 of the amount given by Mrs. Rane.

The amount saved by Vinod every month : 0.025A - (0.025 x 0.8A) = 92.50

0.025A - 0.02A = 92.5

0.005A = 92.5

A = 92.5 / .005

A = 18500

Ans.: Mrs. Rane earns Rs. 18500 per month.