Question

Lakshmi is a cashier in a bank. She has notes of denomination of Rs. 20, Rs. 10 and Rs. 5. The ratio of number of these notes is $1:2:3$. The total cash with Lakshmi is Rs. $1100$. How many notes of Rs. $20$ denomination does she have?

• A. $10$
• B. $20$
• C. $30$
• D. None of the above.

Answer 1

The correct option is B $20$

Let the common multiple be $x$.

Therefore, the number of notes of each denomination are:

Rs. $20=1\left(x\right)=x$ notes

Rs. $10=2\left(x\right)=2x$ notes

Rs. $5=3\left(x\right)=3x$ notes

According to the given condition, total amount with Lakshmi is Rs. $1100$.
$20\left(x\right)+10\left(2x\right)+5\left(3x\right)=1100$

$⟹20x+20x+15x=1100$
$⟹55x=1100$
$⟹x=20$

Therefore, Lakshmi has $20$ notes of Rs. $20$ denomination.