SOLUTION: if 6 men take 3 days to dig 8 ditches, then how long would it take for 4 men to dig 10 ditches? i tried doing 8 ditches x (18men per day) divided by 10 ditches = 14.4 men per di

Algebra ->  Rate-of-work-word-problems -> SOLUTION: if 6 men take 3 days to dig 8 ditches, then how long would it take for 4 men to dig 10 ditches? i tried doing 8 ditches x (18men per day) divided by 10 ditches = 14.4 men per di      Log On


   



Question 844029: if 6 men take 3 days to dig 8 ditches, then how long would it take for 4 men to dig 10 ditches?
i tried doing 8 ditches x (18men per day) divided by 10 ditches = 14.4 men per ditch but i don't know where i went wrong.

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
6 men take 3 days to dig 8 ditches
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1/3 as many men would take 3 times longer
to dig the same number of ditches, so
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2 men take 9 days to dig 8 ditches
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twice as many men take half as long
to dig the same number of ditches, so
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4 men take 9/2 days to dig 8 ditches
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The same number of men take 1/4 of that
time to build 1/4 as many ditches, so
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4 men take 9/8 days to build 2 bridges
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It takes 5 times as long for the same number
of men to dig 5 times as many bridges, so
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4 men take 45/8 days to build 10 bridges
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+45%2F8+=++5+%2B+5%2F8+
4 men take 5 and 5/8 days to build 10 bridges