2012 AMC 10A Problem 3

Below is the professionally curated solution for Problem 3 of the 2012 AMC 10A, from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2012 AMC 10A solutions, or check the answer key.

All of the real AMC 8, AMC 10, AMC 12, and AIME problems in our complete solution collection are used with official legal permission of the Mathematical Association of America (MAA).

Concepts:absolute value

Difficulty rating: 560

3.

A bug crawls along a number line, starting at 2.-2. It crawls to 6,-6, then turns around and crawls to 5.5. How many units does the bug crawl altogether?

99

1111

1313

1414

1515

Solution:

It crawls a distance of 2(6)=4=4 |-2 - (-6)| = |-4| = 4 when it moves from 2-2 to 6.-6. It then travels a distance of 65=11=11 |-6 - 5| = |-11| = 11 as it moves from 6-6 to 5.5.

The total distance is then 4+11=15. 4 + 11 = 15.

Thus, E is the correct answer.

Problem 3 in Other Years