Question

a student has ten posters to pin up on the wall of her room, but there is space for only seven. in how many ways can she choose the posters to be pinned on the wall?

Answer 1

Umpteen ways by making a collage!!
http://image.shutterstock.com/z/stock-photo-travel-in-italy-vintage-collage-113500528.jpg

Answer 2

Writeacher, nice answer showing how mathematicians often assume what to them appears obvious, resulting in poor wording of the question.

number of ways to choose 7 from 10
= C(10,7) = 10!/(3!7!) = 120

Answer 3

10C7