Problem: A student has ten posters to pin up on the walls of her room, but there is space for only

Question

seven. In how many ways can she choose the posters to be pinned up?
Solution: Identify whether it is permutation or combination. Then, give what is ask and select
which formula to be used. Substitute the given values.
Permutation
Combination
n = ______
n = ______
r = ______
r = ______