Percents & Conversions (5.5-5.7)

A town had about 2120 acres of pine trees 40 years ago. Only about 13% of the pine trees remain. How many acres of pine trees remain?

Which proportion represents the correct setup?

Answer explanation

The 2120 is the whole (of) and the part (is) are the trees that remain which we don't know (variable). Always put the percent over 100.

75% of what number is 48?

Set this problem up as a proportion and solve. Type your numerical answer.

Mathematical Equivalence

ON

Zoe bought a new phone case at Best Bet. It was $25 but she had to pay 6% tax. How much did Zoe pay in tax?

Type the correct values into this template to represent the problem above:

​ ​ (a)   % of ​​ (b)   is ​ (c)  

• 6
• 25
• x

Answer explanation

Make sure the percent and the part labels match when you set it up. They should both be 'tax'. The original price is always the whole.

60% of 150 is what number?

Answer explanation

60% (percent)

150 (of-whole)

what number (is-part)

Proportion: 60/100=x/150

In the percent question below, is 52 the percent, whole or part?

52 is 130% of what number?

• Percent

• Whole

• Part

• None of these

Answer explanation

The 52 has the word 'is' next to it so therefore it is the 'part'.

Famous Footwear is have a 20% off sale. If you saved $12.50 on a pair of sneakers, what is the regular price of the sneakers?

Is the answer to the question the percent, whole or part?

• Percent

• Whole

• Part

• None of these

Answer explanation

20% is the percent saved (%)

$12.50 is the money saved (part)

So, the regular price is the original price which is the whole

What does the tip do to the price of the item that you are buying?

• Decreases it

• Increases it

• Doesn't change it

• None of these

756 is what percent of 840?

(Make sure to include the percent sign in your answer!)

Answer explanation

756 (part)

840 (whole)

percent (x)

So, x% of 840 is 756

Then set up as a proporton

Change 15/20 into a percent

(Make sure to include the percent sign in your answer!)

Answer explanation

Remember that percents are out of 100 so make the denominator into 100 by multiplying 20 x 5. Then, multiply the numerator by 5 so 15x5 = 75

Make sure to write the percent sign 75%

You ask 356 people if they enjoy drawing. Of these people, 89 say they do like to draw. What percent of the people surveyed like to draw?

• 400%

• 75%

• 4%

• 25%

Answer explanation

Remember that percents are out of 100. Since it is not easy to make the denominator out of 100, use a proportion.

x/100=89/356

Solve using the cross products.