### All SAT Math Resources

## Example Questions

### Example Question #71 : Percentage

Find the percentage equivalent of the decimal:

**Possible Answers:**

**Correct answer:**

In order to find the percentage equivalent of a decimal, the decimal has to be multiplied by 100. However, since it is multiplication by a power of 10, we can accomplish the same thing, by moving the decimal point 2 places to the right, thus making the number larger. For this problem, that looks like this:

### Example Question #72 : Percentage

Find the percentage equivalent of the decimal:

**Possible Answers:**

**Correct answer:**

In order to find the percentage equivalent of a decimal, the decimal has to be multiplied by 100. However, since it is multiplication by a power of 10, we can accomplish the same thing, by moving the decimal point 2 places to the right, thus making the number larger. For this problem, that looks like this:

### Example Question #7 : How To Find Percentage Equivalent To A Decimal

Find the percentage equivalent of the decimal:

**Possible Answers:**

**Correct answer:**

In order to find the percentage equivalent of a decimal, the decimal has to be multiplied by 100. However, since it is multiplication by a power of 10, we can accomplish the same thing, by moving the decimal point 2 places to the right, thus making the number larger. For this problem, that looks like this:

### Example Question #71 : Percentage

Find the percentage equivalent of the decimal:

**Possible Answers:**

**Correct answer:**

### Example Question #72 : Percentage

Find the percentage equivalent of the decimal:

**Possible Answers:**

**Correct answer:**

### Example Question #73 : Percentage

Find the percentage equivalent of the decimal:

**Possible Answers:**

**Correct answer:**

### Example Question #1 : Percent Of Change

The population of Town *A* is 12,979 people in 1995. The population, when measured again in 2005, is 22,752. What was the change in population to the nearest whole percentage point?

**Possible Answers:**

75%

175%

43%

68%

57%

**Correct answer:**

75%

Since we are looking for the change, we must take the

(Ending Point – Starting Point)/Starting Point * 100%

(22752 – 12979)/12979 * 100%

9773/12979 * 100%

0.753 * 100%

75%

### Example Question #1 : Percent Of Change

A factory produced 2500 units during the month of September. In order to increase production by 12% in the month of October, the factory hired more workers. How many units were produced in October?

**Possible Answers:**

3200

3000

2800

4000

3600

**Correct answer:**

2800

This is a percentage increase problem.

Easiest approach : 2500 x 1.12 = 2800

In this way you are adding 12% to the original.

Using the formula, find 12% of 2500

12/100 = x/2500,

30000 = 100x

300 = x

Now add that to the original to find the new production:

2500 + 300 = 2800

### Example Question #3 : Percent Of Change

The radius of a given circle is increased by 20%. What is the percent increase of the area of the circle.

**Possible Answers:**

40%

20%

100%

44%

144%

**Correct answer:**

44%

If we plug-in a radius of 5, then a 20% increase would give us a new radius of 6 (which is 1.2 x 5). The area of the new circle is π(6)2 = 36π, and the area of the original circle was π(5)2 = 25π . The numerical increase (or difference) is 36π - 25π = 11π. Next we have to divide this difference by the original area: 11π/25π = .44, which multiplied by 100 gives us a percent increase of 44%. The percent increase = (the numerical increase between the new and original values)/(original value) x 100. The algebraic solution gives us the same answer. If radius r of a certain circle is increased by 20%, then the new radius would be (1.2)r. The area of the new circle would be 1.44 π r2 and the area of the original circle πr2. The difference between the areas is .44 π r2, which divided by the original area, π r2, would give us a percent increase of .44 x 100 = 44%.

### Example Question #1 : Percent Of Change

Phoenicia is a grocery store that is expanding quickly.

In 2011 Phoenicia's total sales were $1,800,800.

In 2012 their sales rose to $2,130,346.

By what percentage did the store increase its income from 2011 to 2012.

(Round answer to the nearest tenth.)

**Possible Answers:**

10.5%

16.4%

18.3%

21.0%

19.2%

**Correct answer:**

18.3%

$1,800,800 divided by 100 equals 18,008 and $2,130,346 divided by 18,008 is 118.3

So we know that $2,130,346 is 118.3% of the sales in the previous year. Hence sales increased by 18.3%.

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