Problem C

An Average Quiz

For a recent quiz about averages, the following information is known:

There were three questions on the quiz.

Each question was worth \(5\) marks.

Each question was marked right or wrong (no part marks).

\(30\%\) of the students got all \(3\) questions correct.

\(40\%\) of the students got exactly \(2\) questions correct.

\(25\%\) of the students got exactly \(1\) question correct.

\(5\%\) of the students got no question correct.

Determine the overall class average for this quiz.