Problem:
Homer began peeling a pile of 44 potatoes at the rate of 3 potatoes per minute. Four minutes later Christen joined him and peeled at the rate of 5 potatoes per minute. When they finished, how many potatoes had Christen peeled?
Answer Choices:
A. 20
B. 24
C. 32
D. 33
E. 40
Solution:
After 4 minutes Homer had peeled 12 potatoes. When Christen joined him, the combined rate of peeling was 8 potatoes per minute, so the remaining 32 potatoes required 4 minutes to peel. In these 4 minutes Christen peeled 20 potatoes.
OR
minute12345678​Homer3333333324​Christen555520​running total3691220283644​​
Answer: A​.
The problems on this page are the property of the MAA's American Mathematics Competitions