CEMC Fermat, 2022

Algebra Difficulty 1.3 Junior Find the answer Canada

It takes Pearl 7 days to dig 4 holes. It takes Miguel 3 days to
dig 2 holes. If they work together and each continues digging at these
same rates, how many holes in total will they dig in 21 days?

Pick one

Solution

Since Pearl digs 4 holes in 7 days and $\frac{21}{7} = 3$ , then in 21 days, Pearl
digs $3 \cdot 4 = 12$ holes.

Since Miguel digs 2 holes in 3 days and $\frac{21}{3} = 7$ , then in 21 days, Miguel
digs $7 \cdot 2 = 14$ holes.

In total, they dig $12 + 14 = 26$
holes in 21 days.

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