Question

Sirisha has Rs.$9$ in fifty-paisa and twenty five paise coins. She has twice as many twenty five paise coins as she has fifty paise coins. How many coins of each kind does she have?

Answer 1

Let the number of fifty paise coins $=x$
Therefore the number of twenty five paise coins $=2x$
Value of fifty paise coins $=x\times 50$ paise $=$ Rs.$\frac{50x}{100}=$ Rs.$\frac{x}{2}$
Value of twenty five paise coins $=2x\times 25$ paise $=2x\times \frac{25}{100}$
$=2x\times \frac{1}{4}=$ Rs.$\frac{x}{2}$v
Total value of all coins $=$ Rs.$(\frac{x}{2}+\frac{x}{2})$
But the total value of the money is Rs.$9$
$\Rightarrow$ $\frac{x}{2}+\frac{x}{2}=9$
$\frac{2x}{2}=9$
$\therefore$ $x=9$
Therefore number of fifty paise coins $=x=9$
Number of twenty paise coins $=2x=2\times 9=18$