Problem:
If 3p+34=90,2r+44=76, and 53+6s=1421, what is the product of p,r, and s?
Answer Choices:
A. 27
B. 40
C. 50
D. 70
E. 90
Solution:
From the first equation, 3p+81=90, so 3p=9, and p=2. From the second equation, 2r=32, so r=5. From the third equation, 6s+125=1421, so 6s=1296, and s=4. The product of p,r, and s is 2â‹…5â‹…4=40.
Answer: B​.
The problems on this page are the property of the MAA's American Mathematics Competitions