2 word problems. Thanks for any and all help.  TOPIC_SOLVED

Geometric formulae, word problems, theorems and proofs, etc.

2 word problems. Thanks for any and all help.

Postby kyl367 on Wed Mar 10, 2010 10:53 pm

1. How many cubic yards of concrete are needed to pour a concrete slab 24 feet long, 14 feet wide, and 8 inches thick?
V=Ah
A=LW
A=24 * 14= 336 ft^2
V= 336 * h
V= 336ft^2 * .67 ft =225.12 ft^3
225.12 cubic feet divided by 27= 8.34 cubic yards
2. How many cubic feet of concrete are needed to pour 4 cylindrical pillars 6 feet high with a diameter of 10 inches?
(pi) (r^2) (h)
3.14 X 25 X 72 in =5652 in^2
5652 X 4=22608 in^2
22608 / 1728= 13.08 cubic feet
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Re: 2 word problems. Thanks for any and all help.  TOPIC_SOLVED

Postby maggiemagnet on Wed Mar 10, 2010 11:27 pm

1) Something went wrong with your conversion. Instead of doing the conversion at the end, try working with the fractions at the beginning: (24/3)*(14/3)*(8/3). That way, your answer will already be in "cubic yards".

2) How did you get that 10/12 feet, when squared, equalled 25...? :confused:
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