Nine people (Ann, Ben, Cal, Dot, Ed, Fran, Gail, Hal, and Ida) are in a room. Five of them stand in a row for a picture. In how many ways can this be done if
(e) Hal or Ida (but not both) are in the picture?
(f) Ed and Gail are in the picture, standing next to each other?
- (g) Ann and Ben are in the picture, but not standing next to each other?
The Attempt at a Solution
Given no conditions, the answer would obviously be P(9, 5).
For part "e," one of them can be in the picture. Take both out of the entire pool, and one out of the group, taking pictures. This gives me P(7, 4).
For part "f," I can take two out of both groups (i.e. total and group picture), that leaves me P(7, 3).
For part "g," I don't know how to calculate how they will be ordered, other than to give an incomplete answer of P(7, 3).
I know that all of my answers are wrong.