Question

A sum of $Rs.800$ is in the form of denominations of $Rs.10$ and $Rs.20$. If the total number of notes is $50$, find the number of notes of each type.

Answer 1

$\Rightarrow$ Let the number of notes of $Rs.10$ be $x$

$\therefore$ The number of notes of $Rs.20=50-x$

According to the given condition,

$\Rightarrow$ $10x+20(50-x)=800$

$\Rightarrow$ $10x+1000-20x=800$

$\Rightarrow$ $-10x=800-1000$

$\Rightarrow$ $-10x=-200$

$\therefore$ $x=\frac{200}{10}=20$

$\therefore$ The number of notes of denomination of $Rs.10=20$

$\Rightarrow$ The number of notes of denomination of $Rs.20=50-20=30$