A person has 8 friends of whom 5 will be invited to a party. How many choices are there if 2 of the friends will attend only together? Select one: O a. 26 b. 15 O c. 30 d. 35

How many ways are there to choose 2 different letters from A, B, C, D, E, F? (default: the order does not matter).  a. 15 b. 30 c. 11 d. 10 e. 20 f. None of the other answers is correct.

An ice cream store has 25 flavors to select from. A customer walks in and orders a three​-scoop ice cream cone. How many ways can the customer make this selection if... a. the flavors can be the same and the order is important​? b. the flavors are different and the order is not important​?

Q. There are 10 people stand in a line to take a photo. Two photos are said different if at least two people's positions are changed. How many different photos can we take?