2016 AMC 12A Problem 11

Below is the professionally curated solution for Problem 11 of the 2016 AMC 12A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2016 AMC 12A solutions, or check the answer key.

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Concepts:complementary countinginclusion-exclusiondouble counting

Difficulty rating: 1470

11.

Each of the 100100 students in a certain summer camp can either sing, dance, or act. Some students have more than one talent, but no student has all three talents. There are 4242 students who cannot sing, 6565 students who cannot dance, and 2929 students who cannot act. How many students have two of these talents?

1616

2525

3636

4949

6464

Solution:

The numbers who can sing, dance, and act are 10042=58,100-42=58, 10065=35,100-65=35, and 10029=71,100-29=71, respectively, for a total of 58+35+71=164.58+35+71=164.

Since no student has all three talents, each student has one or two talents, so single-talent students are counted once and two-talent students are counted twice. The number counted twice is 164100=64.164-100=64.

Thus, the correct answer is E.

Problem 11 in Other Years