Question 98857
A seamstress purchases 100 yds. of fabric. She can use it to make 20 skirts and 8 dresses. If she makes 14 dresses will she have enough fabric to make 10 skirts. How many yards of fabric are needed to make each?
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Let "s" be # of yards needed to make a skirt.
Let "d" be # of yards needed to make a dress.
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EQUATIONS:
1st: 20s+ 8d=100
2nd: 10s+14d=100
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Multiply 2nd by 2 to get:
3rd: 20s+28d=200
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Subtract 1st from 3rd to solve for "d"
20d=100
d=5 (# of dresses to be made)
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Substitute into 20s+8d=100 to solve for "s"
20s+8*5=100
20s = 60
s=3 (# of skirts be be made)
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Cheers,
Stan H.