top score math Q test #2 #13

[jihyunjun12]

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i need help. i don't understand the explanation -_-

the roof is 45 ft by 34 ft. each shingles covers an area that is 16 inches wide and 8 inches long. each 5 gallon pail of tar coveres 102 sq ft of roof. how many singles and pails of tar should you purchase to roof the house?

the ansser is 16 pails 1772 singles.

i get the pail part but i don't get the singles part. i did it over and over again. UGHHH SO FRUSTRATING

 

[SuperPink]

Its 35 by 45 ft, not 34 by 45....so that could be your error

So for the shingles part, to get the square feet of the roof:

45 ft x 35 ft = 1575 sq ft

convert feet into inches

1575 sq ft x (144 sq inches/sq ft) = 226,800 sq in

each shingle is 16 in by 8 in, so get the area of the shingle:

16 in x 8 in = 128 sq in

To get number of shingles used, divide roof area (in sq in) by shingle area:

226,800/128 = 1771.87 (round up to nearest integer)

So a grand total of 1772 shingles used

 

[jihyunjun12]

thank you C: