Question

John has 5 friends who want to ride in his new car that can accommodate only 3 passengers at a time. How many different combinations of 3 passengers can be formed from the 5 friends?

Answer 1

10 ways

Explanation:

Step one:

given data

we have 3 passengers to be formed from 5

so the expression for the combination is given as

Cn, r)= n!/r!(n-r)!

substitute

C(5, 3)= 5!/3!(5-3)!

C(5, 3)= 5!/3!(2)!

C(5, 3)= 5*4*3/3!(2)!

C(5, 3)= 5*4*/2*1

C(5, 3)= 20/2

C(5, 3)=10 ways