2016 AMC 12A Problem 2

Below is the professionally curated solution for Problem 2 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:exponent

Difficulty rating: 1020

2.

For what value of xx does 10x1002x=10005?10^x\cdot 100^{2x}=1000^5?

11

22

33

44

55

Solution:

Since 100=102100=10^2 and 1000=103,1000=10^3, the equation becomes 10x104x=1015, 10^x\cdot 10^{4x}=10^{15}, so 105x=1015.10^{5x}=10^{15}. Then 5x=15,5x=15, giving x=3.x=3.

Thus, the correct answer is C.

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