Astudent club has 20 members. how many ways can a club choose a president, secretary, treasurer?

There are 6,840 different combinations of people for president, secretary, and treasurer, assuming that each person may have a single job at a time.

Start with 20 candidates for president.
That leaves 19 people for secretary.
And there are 18 people remaining for treasurer.

20 • 19 • 18 = 6,840

A) for the n row: 22+(n-1)×6therefore,b) 100-22=78that means (n-1)×6=7878÷6=1313+1=1414th row has 100 seats