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 what is the probability of selecting a group that has an average value of equal to or less than $25?
A) 0.45
B) 0.86
C) 0.50
D) 0.35

Question

Quizplus · Accepted Answer

The average value of the three bills is equal to or less than $25 if the sum of the values of the three bills is equal to or less than $75. There are 20 ways to select three bills from the six bills. The sum of the values of the three bills is equal to or less than $75 in 9 of the 20 ways. Therefore, the probability of selecting a group that has an average value of equal to or less than $25 is 9/20 = 0.45.

John Has Six Bills of Paper Money in the Following