2000 AMC 10 Problem 1

Below is the professionally curated solution for Problem 1 of the 2000 AMC 10, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2000 AMC 10 solutions, or check the answer key.

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Concepts:prime factorizationoptimization

Difficulty rating: 960

1.

In the year 2001, the United States will host the International Mathematical Olympiad. Let I,I, M,M, and OO be distinct positive integers such that the product IMO=2001.I \cdot M \cdot O = 2001. What is the largest possible value of the sum I+M+O?I + M + O?

2323

5555

9999

111111

671671

Solution:

Factoring gives 2001=32329.2001 = 3 \cdot 23 \cdot 29.

To maximize the sum with the product fixed, spread the factors as much as possible: take I=1I = 1 and combine the two largest primes, M=3M = 3 and O=2329=667.O = 23 \cdot 29 = 667.

The sum is 1+3+667=671.1 + 3 + 667 = 671.

Thus, the correct answer is E.

Problem 1 in Other Years