2003 AMC 10B Problem 16

Below is the professionally curated solution for Problem 16 of the 2003 AMC 10B, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2003 AMC 10B solutions, or check the answer key.

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Concepts:multiplication principleinequality

Difficulty rating: 1370

16.

A restaurant offers three desserts, and exactly twice as many appetizers as main courses. A dinner consists of an appetizer, a main course, and a dessert. What is the least number of main courses that the restaurant should offer so that a customer could have a different dinner each night in the year 2003?2003?

44

55

66

77

88

Solution:

With mm main courses, the number of dinners is 3m2m=6m2.3 \cdot m \cdot 2m = 6m^2. This must be at least 365.365.

So m2365660.8.m^2 \ge \dfrac{365}{6}\approx 60.8. Since 72=497^2=49 is too small but 82=648^2=64 works, m=8.m=8.

Thus, the correct answer is E.

Problem 16 in Other Years