A ratio is a comparison of two numbers. There are three ways to express the ratio of 3 to 5. You can write: 3 to 5 or 3:5 or 3/5. This last way is the same as a fraction. Thus, a ratio can also be expressed as a fraction.

Express the ratio of 1 to 3 as a fraction.- 1/3
- 2/4
- 1/2

Express the ratio 4:3 as a fraction.

- 4/3
- 3/4
- 10/1

Write the ratio 10 to 7 as a fraction.

- 10/10
- 7/10
- 10/7
- 7/7

The fraction 5/6 represents the ratio of 5 to _____.

- 5
- 6
- 7
- 8

Express the ratio of 10 to 2 as a fraction in lowest terms.

- 10/2
- 5
- 1/5

Show the ratio of 16 tires to 4 cars in lowest terms.

- 4:1
- 16:4
- 8:2

Show the ratio of 20 dollars to 26 ounces of vodka.

- 10:13
- 26:20
- 20:26

Show the ratio of 100 Canadian dollars to 80 American dollars.

- 10:8
- 5:4
- 1:5
- 5:2

You can simplify a ratio with decimals as a ratio of whole numbers by multiplying by 10, 100, 1000, etc. For example, 0.2/0.5 can be simplified by multiplying the numerator and denominator by 10 to get 2/5. This is similar to finding equivalent fractions as in Section 3.

Simplify 0.5/0.3- 3/5
- 30/50
- 60/100
- 5/3

Simplify 0.01/0.06

- 10/6
- 4/3
- 1/6

Simplify 0.003/0.1 (Hint: Multiply the numerator and denominator by 1000).

- 3/10
- 3/100
- 3/1000

Simplify 0.05/0.011

- 50/11
- 5/11
- 5/110
- 50/110

Simplify 4/5.31

- 400/531
- 40/531

A

**percent**is a ratio with a denominator of 100. The ratio 5/100 also represents 5 percent (symbolized by 5%). What percent does 53/100 represent?- 100%
- 48%
- 53%

64/100 is 64 one-hundredths or 64%. 23/100 is 23 one-hundredths or _____ percent.

- 23
- 77
- 52

113/100 is _____ percent.

- 113
- 1.13
- 11300

83% is what ratio?

- 83/100
- 83/10
- 83/1

5% is what ratio?

- 40/100
- 20/100
- 8/100
- 5/100

530% is what ratio in lowest terms?

- 53/10
- 530/100
- 10/53

Since percents can be shown as fractions with 100 as the denominator, they can also be shown as decimals. For example, 33/100 is also 0.33 and is also 33%.

What percent is represented by the number 0.65? (Hint: 0.65 = 65/100)- 6.5%
- 65%
- 650%

What percent is represented by the number 1.23 (Hint: 1.23 = 123/100)?

- 123%
- 12.3%
- 12300%
- 1.23%

What percent is represented by the number 0.3?

- 0.3%
- 3%
- 15%
- 30%

As you might have guessed, to convert a decimal to a percent, you move the decimal two places to the right (which is what you do when you multiply by 100).

What percent is given by the number 0.655??- 655%
- 65.5%
- 6.55%
- 0.655%

What percent is given by the number 250? (Hint: Move the decimal two places to the right)

- 2.5%
- 25%
- 250%
- 25000%

What percent is given by the number 34.56?

- 0.3456%
- 345.6%
- 3456%
- 34560%

What percent is given by the number 0.000543?

- 0.0543%
- 5.43%
- 543%

Figure out what ‘x’ should be in the following: 1/3 = x/12. (Hint: Multiply the numerator and denominator (of 1/3) by the same number to find an equivalent ratio with 12 as the denominator)

- x = 4
- x = 2
- x = 1

Figure out what ‘x’ should be in this: 2/5 = 5/x

- 2.5
- 25
- 100
- 50

Figure out what ‘x’ should be in this: x/5 = 3/15

- x = 3
- x = 2
- x = 1

Figure out what ‘x’ should be: 1 to 3 = 3 to x

- x = 10
- x = 9
- x = 3
- x = 1

Figure out what ‘x’ should be: 3:5 = 300:x

- x = 1000
- x = 100
- x = 50
- x = 500

The ratio of eyes to noses is 2:1. If there are 400 eyes then how many noses are there?

- 100
- 200
- 400

There are 2 pieces of bread for every 3 slices of salami. How many pieces of bread are there if there are 15 slices of salami?

- 5
- 9
- 10
- 12

Every litre of fuel for an outboard motor has 900mL of gasoline and 100mL of oil. If there is 10L of fuel in the tank then how many litres of oil is are the tank?

- 1
- 2
- 3
- 4

To find 20% of a certain number, multiply that number by the decimal equivalent of 20%, which is 0.2. This is the same as multiplying the number by the fraction 20/200.

What is 20% of 5?- 4
- 3
- 2
- 1

It’s important to note that finding what number is 20% of 5 is the same as finding x in 20/100 = x/5. This is true because the 20/100 represents 20% and the x/5 should also represent 20% since x is 20% of 5.

What equation could you make for finding 25% of 60?- 25/100 = x/60
- 25/100 = 60/x
- 25/60 = x/100
- 25/60 = 100x

What is 25% of 60?

- 10
- 15
- 20
- 25

What equation can you make for finding 110% of 20?

- 110/100 = x/20
- 110/100 = 20/x
- 100/110 = x/20
- 100/20 = x/110

What is 110% of 20?

- 16
- 30
- 22

What is 12% of 50?

- 4
- 6
- 8
- 12

A common application of percents is to increase a number by a certain percent. For example, to increase 10 by 20%, you multiply 10 by 120% = 120/100 = 1.2 and you get 10 X 1.2 = 12.

What is 10 increased by 30%?- 3
- 7
- 13
- 16

To increase a number by a given percent, multiply that number by 100 plus the percent. So, to increase the number 50 by 12%, you multiply 50 by 112% (which is the same as finding 112% of the number).

What is 50 increased by 12%?- 52
- 56
- 60
- 80

What is 80 increased by 20%?

- 88
- 90
- 92
- 96

What is 240 increased by 15%?

- 276
- 284
- 292
- 304

What is 135 increased by 60%?

- 185
- 192
- 216
- 224

If a pair of shoes costs $25 before a 15% sales tax is added then what is the cost after tax?

- $28.75
- $30.25
- $32.55
- $3.75

If a donut costs 90 cents before a 7% sales tax is applied then what is the cost with tax (rounded off to the nearest cent)?

- $0.94
- $0.95
- $0.96
- $0.97

To subtract a percentage from a number, you multiply the number by 100 minus the percentage given. For example, to subtract 20% from 50, you multiply 50 by 80% (100 - 20).

Subtract 10% from 50.- 45
- 40
- 35
- 25

Subtract 15% from 100.

- 15
- 40
- 70
- 85

Subtract 25% from 300.

- 275
- 225
- 200
- 175

Subtract 12% from 150.

- 120
- 135
- 132
- 138

A sweater costs $40 before a 15% discount. What is the cost after the discount is applied?

- 30
- 32
- 34
- 35

A Depeche Mode CD costs $30 before a 95% discount is applied. What is the cost after the discount is applied?

- $4.50
- $3.00
- $2.25
- $1.50

If I drink 13% of the Pepsi from a 2000mL bottle of Pepsi then how much Pepsi is left in the bottle?

- 1740mL
- 1860mL
- 1940mL
- 1987mL

You can reverse the process of finding a percent of a number to find the number given how much a certain percent of it is. For example, you can find the number that 40 is 80% of by using the equation: 80/100 = 40/x. Can you see that this is similar to our previous equation? This time 40/x represents 80%, just as 80/100 represents 80%. What is x in this equation?

- 25
- 30
- 50
- 60

30 is 60% of what number? (Hint: use 60/100 = 30/x)

- 40
- 45
- 50
- 60

80 is 20% of what number?

- 400
- 500
- 600
- 200

35 is 50% of what number?

- 55
- 70
- 85
- 100

If I drank 50mL of beer and that was 20% of the beer in the bottle then how much beer was in the bottle originally (in mL)?

- 250mL
- 500mL
- 750mL
- 1250mL

If 40% of the water used in a house is used by the toilet and the toilet uses 30L of water in a day then how much total water is used in this house in a day?

- 75
- 100
- 125
- 135