Percent Proportion

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Percent Proportion

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Percent

Means ‘of a hundred’

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The Percent Proportion(s)

You will use a proportion to solve most percent problems.

Remember: the percent will always be related to a hundred.

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The Percent Proportion(s)

isof

%100=

The percent % is always over 100.

‘is’ is the number with the word ‘is’

‘of’ is the number with the word ‘of’ 100 is always on the bottom.

This proportion can be used when dealing with simple percent statements such as:“What is 10% of 100?”“10 is what percent of 100?”“10 is 10% of what number?”

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50 is what percent of 230?

Use the proportion. isof

%100=

50230

x100=

Cross multiply to get the answer.

21.73913043or

x = 21.7%

50 is 21.7% of 230

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What is 85% of 40?

Use the proportion. isof

%100=

x40

85100=

Cross multiply to get the answer.

x = 34

34 is 85% of 40

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25% of what number is 400?

Use the proportion. isof

%100=

400x

25100=

Cross multiply to get the answer.

x = 1600

25% of 1600 is 400

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What is 175% of 80?

Use the proportion. isof

%100=

x80

175100=

Cross multiply to get the answer.

x = 140

140 is 175% of 80

919 is 25% of what number?

What percent of 256 is 64?

What is 45% of 178?

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19 is 25% of what number?

Use the proportion. isof

%100=

19x

25100=

Cross multiply to get the answer.

x = 76

19 is 25% of 76

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What percent of 256 is 64?

Use the proportion. isof

%100=

64256

x100=

Cross multiply to get the answer.

x = 25%

25% of 256 is 64

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What is 45% of 178?

Use the proportion. isof

%100=

x178

45100=

Cross multiply to get the answer.

x = 80.1

80.1 is 45% of 178

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You can also do a literal translation of the question:

What percent of 256 is 64?

We don’t know “WHAT PERCENT” is so we put an X“OF” means multiply.256 is already in ‘math’ form.“IS” means equals.And 64 is already in ‘math’ form.

So we have:

X * 256 = 64 and solve as normal