Ann, Mara, Jenny, Tina, and Sue are sisters. Two of the five sisters must help their father at this business each Saturday. How many combinations of two sisters are possible?
2 * 5 = 10
Blob's answer is not correct.
This is like choosing 2 of 5, which is
C(5,2) = 5!/(3!2!) = 20
10. Keep in mind order doesn't matter so half of 20.
12 combinations
Ann Mara
Ann Sue
Mara Jenny
Mara Tina
Mara Sue
Jenny Ann
Jenny Tina
Jenny Sue
Tina Ann
Tina Sue
Sue Ann
Sue Tina