If 12 workers can plant 1320 seedlings in five hours, how long would it take 8 workers or 15 workers?

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Answer 1 · 2017-08-12T15:28:12

$8$ workers = $7 1/2$ hours
$15$ workers = $4$ hours

Firstly divide $1320$ by $12$ to get $110$ .

$1320/12 = 110$

Then divide $110$ by $5$ to get the amount planted per person per hour, which is $22$ .

$110/5 = 22$

Then times $22$ by $8$ to get $176$ , then divide that by $1320$ to get the amount of hours, which is $7 1/2$ .

$22 times 8 = 176$

and,

$1320/176 = 7 1/2$ hours.

Then do exactly the same for 15 workers.

$22 times 15 = 330$

$1320/330 = 4$ hours.