2021 AMC 12B Spring Problem 1 — Solution | LIVE by Po-Shen Loh

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2021 AMC 12B Spring Problem 1

Attempt Problem 1 of the 2021 AMC 12B Spring below, then check your answer against the professionally curated solution from LIVE by Po-Shen Loh. You can also try the full timed exam, view all 2021 AMC 12B Spring solutions, or check the answer key.

All problems are used with official legal permission of the Mathematical Association of America (MAA).

1.

How many integer values of $x$ satisfy $|x| \lt 3\pi?$

$9$

$10$

$18$

$19$

$20$

Answer: D

Concepts:absolute value estimation

Difficulty rating: 870

Solution:

Since $3\pi \approx 9.42,$ the inequality $|x| \lt 3\pi$ means $-9.42 \lt x \lt 9.42.$

The integers in this range run from $-9$ to $9,$ giving $19$ values.

Thus, the correct answer is D.

Problem 2#2 →

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