What would be the cost in dollars of nails for a fence 88 feet long if one needs 9 nails per foot of fence, there are 36 nails in a pound, and they sell for 69 cents per pound?

2 Answers
Feb 28, 2015

Arrange the ratios so that when multiplied together the units of measurement cancel out (except for the required units of the answer.

#(88 ft )/(fence)xx(9 nails)/(ft)xx(1 pound)/(36 nails)xx($ 0.69)/(1 pound)#

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#= ($14.96)/(fence)#

Feb 28, 2015

You get:
#88 ft *9 (nails)/(ft)=792 nails#
#(792nails)/(36(nails)/(pound))=22 pounds#

(hope I am right with US units of currency!!!)