The rule of sum in discrete  mathematics is a way to count a set of objects into independent elements. The  rule of sum presents a situation an idea  that if one situation can occur in \(A\) ways and another situation can occur in \(B\) ways, then there are \(A+B\) ways that one of  these types of situations may occur.

For example, a restaurant  serves fifteen entrees that contain meat, five entrees that contain fish and