Problem:
9×113×5​×3×5×77×9×11​=
Answer Choices:
A. 1
B. 2
C. 49
D. 491​
E. 50
Solution:
9×113×5​×3×5×77×9×11​=3×5×7×9×113×5×7×9×11​=1
Answer: A​.
The problems on this page are the property of the MAA's American Mathematics Competitions