1971 AMC 12 Problem 2

Attempt Problem 2 of the 1971 AMC 12 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 1971 AMC 12 solutions, or check the answer key.

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b

men take

c

days to lay

f

bricks, then the number of days it will take

c

men working at the same rate to lay

b

bricks is:

fb^2

\frac{b}{f^2}

\frac{f^2}{b}

\frac{b^2}{f}

\frac{f}{b^2}

Find the number of bricks laid by one man in one day

The rate is

\frac{f}{bc}

bricks per man-day

The rate is

\frac{f}{bc}

bricks per man-day. Thus

c

men lay

\frac{f}{b}

bricks per day, so laying

b

bricks takes

\frac{b}{\frac{f}{b}}=\frac{b^2}{f}

days.

Therefore, the correct answer is D.

Problem 2 in other years