Problem:
Sangho uploaded a video to a website where viewers can vote that they like or dislike a video. Each video begins with a score of , and the score increases by for each like vote and decreases by for each dislike vote. At one point Sangho saw that his video had a score of , and that of the votes cast on his video were like votes. How many votes had been cast on Sangho's video at that point?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Let be the number of votes cast. Then of them were like votes, and of them were dislike votes. The current score for Sangho's video is then . Thus .
The problems on this page are the property of the MAA's American Mathematics Competitions