The correct option is
C $5
Cost of books =
$125
To find the cost of each book, we check whether 125 is divisible
by 3, 4 or 5.
Divisibility rule of 3 is:
If the sum of all the digits of a number is divisible by 3, then the number is divisible by 3.
Checking for 125, we get:
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1204175/original_Screenshot_2021-06-25_230558.png)
Now, let's check for the
divisibility rule of 4.
Divisibility rule of 4 is:
If the last two digits of a number is divisible by 4, then the number is also divisible by 4.
Checking for 125, we get:
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1204177/original_Screenshot_2021-06-25_230928.png)
Lastly, the divisibility rule of 5 is:
If the digit at ones place of a number is 0 or 5, then the number is divisible by 5.
Checking for 125, we get:
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/1204179/original_Screenshot_2021-06-25_230502.png)
We can observe that
$125 is divisible by 5 only.
Hence, the cost of each book is
$5.