Question

How many ways can Pete, Mary, Sue, and Joe stand in a line if Joe and Sue cannot stand next to each other?

A.
4
B.
6
C.
12
D.
16
E.
18

Answer 1

There are 12 (C) because

Pete, Joe, Mary, Sue

Pete, Sue, Mary, Joe

Mary, Sue, Pete, Joe

Mary, Joe, Pete, Sue

Sue, Mary, Joe, Pete

Sue, Mary, Pete, Joe

Sue, Pete, Joe, Mary

Sue, Pete, Mary, Joe

Joe, Mary, Sue, Pete

Joe, Mary, Pete, Sue

Joe, Pete, Sue, Mary

Joe, Pete, Mary, Sue