John has six bills of paper money in the following denominations: $1, $5, $10, $20, $50, and $100 If he selects 3bills at a time how many, how many groups can be formed?
A) 20
B) 10
C) 30
D) 15

Question

Quizplus · Accepted Answer

There are 6 ways to choose the first bill, 5 ways to choose the second bill, and 4 ways to choose the third bill. So, there are 6 * 5 * 4 = 120 ways to choose 3 bills from 6 bills. However, since the order of the bills does not matter, we need to divide by 3! to account for the overcounting. So, there are 120 / 3! = 20 groups that can be formed.

John Has Six Bills of Paper Money in the Following