Question

Ninety percent of the ninth grade students at Richbartville High School take algebra. If 180 ninth grade students take algebra, how many ninth grade students do not take algebra?

Answer 1

90% of the students takes algebra
⇒ 100 - 90 = 10% do not take algebra

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Find 1%:
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90% = 180
1% = 180 ÷ 90
1% = 2

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Find 10%
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1% = 2
10% = 2 x 10
10% = 20

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Answer: 20 students do not take algebra.
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