Answer:
William must have paid about $30 for his bounced check of $7.50.
Explanation:
The bank charges this much in order to deter people from frivolously writing checks that they know would bounce and to pay for the service they render to having to return the bounced. I think that it is a reasonable charge because some people have refused to learn. Some others think that they can continue with their duplicity at all times. There must a way to check their unkind actions of creating unnecessary and irresponsible work.