Question

Solve the following:

A lady went to a bank with Rs. 100000. She asked the cashier to give her Rs. 500 and Rs. 1000 currency notes in return. She got 175 currency notes in all. Find the number of each kind of currency notes.

Answer 1

Given, total number of currency notes=175
Let the total number of notes of Rs. 500 be x.
Then, total number of notes of Rs. 1000=175-x
$\because$ Total amount which lady had=Rs. 100000
According to the question,
$500x+(175-x)1000=100000$
$\Rightarrow 500x+175000-1000x=100000$
$\Rightarrow -500x=100000-175000$
$\Rightarrow x=-75000\times \left(\frac{-1}{500}\right)$
$\therefore x=150$
Therefore, total number of notes of Rs. 500=150
and total number of notes of Rs. 1000=175-150=25