Question

A coin collector has $45 in just dimes and quarters in a piggy bank he counted all the coins and there are 240 total how many each type of each coin does he have

Answer 1

Answer:

The number of dimes are 100 and number of quarters are 140.

Step-by-step explanation:

Let the number of dimes be 'd' and quarters be 'q'.

Given:

The sum of amount is $45.

The total number of coins are 240.

1 dime = $0.10

∴ 'd' dimes = $\ 0.10d$

1 quarter = $0.25

∴ 'q' quarters = $\ 0.25q$

Now, as per question:

$d+m=240-----1\\0.1d+0.25q=45---2$

Multiplying equation (1) by -0.1 and adding the result to equation (2), we get:

$-0.1d-0.1q=240\times -0.1\\-0.1d-0.1q=-24\\0.1d+0.25q=45\\-----------\\0.15q=21\\q=\frac{21}{0.15}=140\\\\d=240-q=240-140=100$

Therefore, the number of dimes are 100 and number of quarters are 140.