Problems with Percent

Find 40% of 200

• 80

• 8

• 800

• 40

Answer explanation

Simply multiply

200 x .40 = 80

Eric received a 20% discount on a game that costs $50. How much did he pay?

• 40

• 10

• 20

• $30

Answer explanation

Discount means subtract from 100

100 - 20 = 80% of the price

Now multiply

50 x .80 = $40

Rayvon can do 40 pushups. He increased that number by 25%, how mnay pushups can he now do?

• 50

• 40

• 10

• 65

Answer explanation

Increased by 25%...we need to add to 100

100 + 25 = 125%

Now multiply

40 x 1.25 = 50 pushups

An xbox costs $300. There is a 20% discount and a 5% tax. How much did Judson pay for the xbox?

• $252

• 30

• 120

• 240

Answer explanation

Discount first subtract from 100

100 - 20 = 80%

Multiply

300 x .80 = 240

Now add the tax

100 + 5 = 105%

Finally multiply (by new price)

240 x 1.05 = $252

Chris watched 40 minutes of Netflix on Monday, on Tuesday he watched 30 minutes. What was his percent change

• 25% increase

• 25% decrease

• 50% increase

Answer explanation

Use the percent change formula

Original: 40

New: 30

= 25% decrease

Match the following

• 100 + 4 = 104%

• 20% tip

• 100 + 5 = 105%

• 30% discount

• 100 - 30 = 70%

• 5% tax

• 100 - 20 = 80%

• 20% decrease

• 100 + 20 = 120%

• 4% mark up

Mr. Mason thought he would make 5 mistakes in class. He actually made 8, what is his percent error?

• 37.5%

• 60%

• 30%

• 75%

What is 3% as a decimal?

• 0.03

• 0.3

• 3.0

• 0.003

Careful!

What is 2.5% as a decimal?

• 0.025

• 0.25

• 2.5

• 0.0025

Mr. Mason drives to school at 60 miles per hour. Once he gets off the highway, he decreases his speed by 55%. What speed does he drive once he gets off the highway?

• 27

• 33

• 22

• 15

Answer explanation

Decreases spee 55% means we need to subtract from 100

100 - 55 = 45%

Now multiply

60 x .45 = 27 mph