## it costs \$5 to mow a rectangular field 40m long and 25m wide

Geometric formulae, word problems, theorems and proofs, etc.
little_dragon
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### it costs \$5 to mow a rectangular field 40m long and 25m wide

It costs \$5.00 to mo a rectangular field 40 m long and 25 m wide. How much will it cost to mow a similar field 67.5 m wide at the same rate?

I know I'm supposed to use similar figures and ratios. I get (40 m)(25 m) = 1000 m^2 for \$5, so \$0.005/m^2. The similar rectangles are 40-by-25 and 67.5-by-x, so using ratios gives me x = 42.1875. The area of the similar field is (67.5 m)(42.1875 m) = 2847.65625 m^2, so the cost is about \$14.24. But this is wrong?

stapel_eliz
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It costs \$5.00 to mo a rectangular field 40 m long and 25 m wide. How much will it cost to mow a similar field 67.5 m wide at the same rate?
I think you crossed the dimensions...?

You appear to have used the ratio 40/25 = 67.5/x. I believe you should have:

. . . . .length : width = 40 : 25 = x : 67.5

Try it again using the ratio 40/25 = x/67.5.

Eliz.

little_dragon
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### Re: it costs \$5 to mow a rectangular field 40m long and 25m wide

D'oh! Thanks!

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