Question

A boy has $x$ coins of $50$ paise each, $2x$ coins of $25$ paise each, $4x$ coins of $10$ paise each and $8x$ coins of $5$ paise each. Find the number of $5$ paise coins if the value of all the coins is Rs. $9$.

• A. $40$
• B. $56$
• C. $43$
• D. $55$

Answer 1

The correct option is A $40$

Given, $0.50x+0.25\left(2x\right)+0.10\left(4x\right)+0.05\left(8x\right)=9$

$\Rightarrow 0.50x+0.50x+0.40x+0.40x=9$

$\Rightarrow 1.80x=9$

$\Rightarrow x=\frac{9}{1.8}=5$

Number of $5$ pasie coins $=8x=8\left(5\right)=40$