2009 AMC 10A Problem 8

Below is the professionally curated solution for Problem 8 of the 2009 AMC 10A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2009 AMC 10A solutions, or check the answer key.

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Concepts:percentagework backwards

Difficulty rating: 1060

8.

Three generations of the Wen family are going to the movies, two from each generation. The two members of the youngest generation receive a 50%50\% discount as children. The two members of the oldest generation receive a 25%25\% discount as senior citizens. The two members of the middle generation receive no discount. Grandfather Wen, whose senior ticket costs $6.00,\$6.00, is paying for everyone. How many dollars must he pay?

3434

3636

4242

4646

4848

Solution:

The senior ticket costs $6,\$6, which is 34\dfrac34 of the full price, so a full ticket costs 436=$8,\dfrac43 \cdot 6 = \$8, and a child ticket costs 128=$4.\dfrac12 \cdot 8 = \$4.

The total is 2(6+8+4)=$36.2(6 + 8 + 4) = \$36.

Thus, the correct answer is B.

Problem 8 in Other Years