A father gives 1% of his monthly salary to his two sons as pocket mone

1.	A father gives 1% of his monthly salary to his two sons as pocket money. The elder son gets 80% of the total amount given to the two sons and he spends 80% of his share. If he saves Rs 20 every month, then the monthly salary of the father is (a) Rs 10000 (b) Rs 11500 (c) Rs 12000 (d) Rs 12500
Answer» (d) Rs 12500 Let the father’s salary be Rs x. Then, Part of salary given to the two sons as pocket money =\(\frac{X}{100}\) Share of the elder son = \(\frac{80}{100}\) x \(\frac{X}{100}\) = \(\frac{4X}{500}\) Expenditure of the elder son = \(\frac{80}{100}\) x \(\frac{4X}{500}\) = \(\frac{16X}{2500}\) \(\therefore\) Savings of the elder son = \(\frac{4X}{500}\)- \(\frac{16X}{2500}\) = \(\frac{4X}{2500}\) Given, \(\frac{4X}{2500}\) = Rs 20 \(\Rightarrow\) x = Rs \(\frac{20\times 2500}{4}\) =Rs 12500.

A father gives 1% of his monthly salary to his two sons as pocket money. The elder son gets 80% of the total amount given to the two sons and he spends 80% of his share. If he saves Rs 20 every month, then the monthly salary of the father is (a) Rs 10000 (b) Rs 11500 (c) Rs 12000 (d) Rs 12500

Answer»

(d) Rs 12500

Let the father’s salary be Rs x. Then,

Part of salary given to the two sons as pocket money =\(\frac{X}{100}\)

Share of the elder son = \(\frac{80}{100}\) x \(\frac{X}{100}\) = \(\frac{4X}{500}\)

Expenditure of the elder son = \(\frac{80}{100}\) x \(\frac{4X}{500}\)

= \(\frac{16X}{2500}\)

\(\therefore\) Savings of the elder son = \(\frac{4X}{500}\)- \(\frac{16X}{2500}\) = \(\frac{4X}{2500}\)

Given, \(\frac{4X}{2500}\) = Rs 20

\(\Rightarrow\) x = Rs \(\frac{20\times 2500}{4}\) =Rs 12500.