Question

In how many ways can a person pay an amount rs 120 using two rupee or five rupee coins

Answer 1

The person can pay 120 Rs in infinity many times

Answer 2

Answer:

There are 13 ways can a person pay an amount Rs.120 using two rupee or five rupee coins.

Step-by-step explanation:

To find : In how many ways can a person pay an amount Rs.120 using two rupee or five rupee coins ?

Solution :

Let x and y be the required number of coins of 2 and 5 respectively.

According to question,

$2x+5y=120$

Now, We take out the values of x and y

$2x=120-5y$

$x=\frac{120-5y}{2}$

$x=60-\frac{5y}{2}$

Condition on y to get x are

1. y should be an even number to ensure x is an integer.

2. Minimum value of y is 0

3. Let's try to find max y by setting x to 0

$0=60-\frac{5y}{2}$

$\frac{5y}{2}=60$

$5y=120$

$y=\frac{120}{5}$

$y=24$

So, y can be all even numbers till 24 including 0.

i.e. y=0,2,4,6,8,10,12,14,16,18,20,22,24

Total 13 solutions.

Therefore, There are 13 ways can a person pay an amount Rs.120 using two rupee or five rupee coins.