Finding Percent of a Number

Show your work for each problem.

1.
What is 10% of 50?
1. a)5
2. b)10
3. c)50
4. d)15
Answer: 5
10% of 50 = . Quick tip: To find 10%, just move the decimal one place left!
2.
What is 50% of 80?
1. a)8
2. b)20
3. c)40
4. d)60
Answer: 40
50% of 80 = . Remember: 50% = half = divide by 2.
3.
What is 25% of 100?
Answer: 25
25% of 100 = . Since 25% = 1/4, finding 25% is the same as dividing by 4.
4.
What is 20% of 45?
Answer: 9
20% of 45 = . Convert 20% to 0.20, then multiply.
5.
A shirt costs 40 euros and is on sale for 25% off. How much do you save?
1. a)8 euros
2. b)15 euros
3. c)10 euros
4. d)25 euros
Answer: 10 euros
25% of 40 = euros. You save 10 euros, so the sale price is 30 euros.
6.
Find 15% of 80.
Answer: 12
1. What is 10% of 80? 8
2. What is 5% of 80? (Half of 10%) 4
3. What is 15% of 80? (10% + 5%) 12
7.
What is 30% of 250?
Answer: 75
30% of 250 = . Alternative: 10% of 250 = 25, so 30% = 3 25 = 75.
8.
Which is greater: 40% of 50 or 30% of 80?
1. a)40% of 50
2. b)Cannot determine
3. c)They are equal
4. d)30% of 80
Answer: 30% of 80
40% of 50 = . 30% of 80 = . Since 24 > 20, 30% of 80 is greater.
9.
A restaurant bill is 55 euros. You want to leave a 20% tip. What is the total amount you will pay?
Answer: 66
1. What is 10% of 55? 5.5
2. What is 20% of 55? (Double the 10%) 11
3. What is the total (bill + tip)? 66
10.
What is 8% of 450?
Answer: 36
8% of 450 = . Check: 10% of 450 = 45, and 8% should be less, which it is!
11.
A jacket costs 120 euros. It is on sale for 35% off. What is the sale price?
Answer: 78
1. What is 10% of 120? 12
2. What is 30% of 120? (Three times 10%) 36
3. What is 5% of 120? (Half of 10%) 6
4. What is 35% of 120? (30% + 5%) 42
5. What is the sale price? 78
12.
A test has 60 questions. You need 75% to pass. How many questions must you get right?
1. a)40
2. b)50
3. c)45
4. d)48
Answer: 45
75% of 60 = . Or: 75% = 3/4, so questions.
13.
A laptop costs 800 euros. First, it gets a 15% discount. Then, you must pay 10% tax on the discounted price. What is the final price?
Answer: 748
1. What is 15% of 800? 120
2. What is the price after the 15% discount? 680
3. What is 10% of 680 (the tax)? 68
4. What is the final price (discounted price + tax)? 748
14.
What is 125% of 60?
Answer: 75
125% of 60 = . Or: 100% of 60 = 60, plus 25% of 60 = 15, so 125% = 60 + 15 = 75.
15.
A store has a sale: 20% off everything. Then members get an additional 10% off the sale price. If a coat originally costs 150 euros, what does a member pay?
Answer: 108
1. What is 20% of 150? 30
2. What is the sale price after 20% off? 120
3. What is the member's additional 10% off 120? 12
4. What does the member pay? 108
16.
What is 0.5% of 600?
Answer: 3
0.5% of 600 = . Alternative: 1% of 600 = 6, so 0.5% = 6 / 2 = 3.
17.
A phone costs 500 euros. The price increases by 12%. What is the new price?
Answer: 560
1. What is 10% of 500? 50
2. What is 2% of 500? 10
3. What is 12% of 500? (10% + 2%) 60
4. What is the new price after the increase? 560
18.
Maria scored 45 points on a test. This was 90% of the total points. How many points was the test worth in total?
Answer: 50
1. If 45 is 90%, what is 10%? 5
2. What is 100% (the total)? 50