Percent Decrease Master Quiz: Master Percent Decrease Quiz

1) A $600 TV was discounted by 15% then reduced by $51. What is the final price?

$459

$460

470

480

After 15% off: 600 times 0.85 = $510. Then subtract $51: 510 minus 51 = $459. Option B gives $460, off by $1. Option C gives $470, which ignores the full $51 reduction. Option D gives $480, which only accounts for part of the first discount. Only $459 correctly applies both the percentage discount and the fixed dollar reduction.

Explanation

After 15% off: 600 times 0.85 = $510. Then subtract $51: 510 minus 51 = $459. Option B gives $460, off by $1. Option C gives $470, which ignores the full $51 reduction. Option D gives $480, which only accounts for part of the first discount. Only $459 correctly applies both the percentage discount and the fixed dollar reduction.

2) A company produced 10,000 units last year and 8,000 this year. What is the percent decrease?

15%

18%

20%

25%

Decrease = 10,000 minus 8,000 = 2,000. Percent decrease = (2,000 divided by 10,000) times 100 = 20%. Option A gives 15%, meaning a drop of 1,500 units. Option B gives 18%, meaning a drop of 1,800 units. Option D gives 25%, meaning a drop of 2,500 units. Only 20% matches the actual decrease of 2,000 units.

Explanation

Decrease = 10,000 minus 8,000 = 2,000. Percent decrease = (2,000 divided by 10,000) times 100 = 20%. Option A gives 15%, meaning a drop of 1,500 units. Option B gives 18%, meaning a drop of 1,800 units. Option D gives 25%, meaning a drop of 2,500 units. Only 20% matches the actual decrease of 2,000 units.

3) A bicycle worth $240 was reduced by 25% then taxed 10% on the reduced price. What is the final cost?

$180

$198

$200

$210.00

After 25% off: 240 times 0.75 = $180. After 10% tax on the reduced price: 180 times 1.10 = $198. Option A gives $180, which is only after the discount before the tax is applied. Option C gives $200, which has an error in either the discount or tax step. Option D gives $210, which overstates the tax amount. Only $198 correctly applies both the reduction and the tax.

Explanation

After 25% off: 240 times 0.75 = $180. After 10% tax on the reduced price: 180 times 1.10 = $198. Option A gives $180, which is only after the discount before the tax is applied. Option C gives $200, which has an error in either the discount or tax step. Option D gives $210, which overstates the tax amount. Only $198 correctly applies both the reduction and the tax.

4) A phone cost $500, decreased by 30% then by another 10%. What is the final price?

$300

$310

$315

$320

After 30% off: 500 times 0.70 = $350. After 10% off the new price: 350 times 0.90 = $315. Option A gives $300, which would require a combined 40% off in one step. Option B gives $310, which has an error in the second step. Option D gives $320, which does not match either calculation. Only $315 correctly applies both successive discounts.

Explanation

After 30% off: 500 times 0.70 = $350. After 10% off the new price: 350 times 0.90 = $315. Option A gives $300, which would require a combined 40% off in one step. Option B gives $310, which has an error in the second step. Option D gives $320, which does not match either calculation. Only $315 correctly applies both successive discounts.

5) A book's price decreased from $50 to $37.50. What is the percent decrease?

20%

22%

25%

30%

Decrease = 50 minus 37.50 = $12.50. Percent decrease = (12.50 divided by 50) times 100 = 25%. Option A gives 20%, meaning a drop of $10. Option B gives 22%, meaning a drop of $11. Option D gives 30%, meaning a drop of $15. Only 25% matches the actual decrease of $12.50.

Explanation

Decrease = 50 minus 37.50 = $12.50. Percent decrease = (12.50 divided by 50) times 100 = 25%. Option A gives 20%, meaning a drop of $10. Option B gives 22%, meaning a drop of $11. Option D gives 30%, meaning a drop of $15. Only 25% matches the actual decrease of $12.50.

6) A decrease from 90 to 72 represents a 20% decrease.

True

False

The answer is True. Decrease = 90 minus 72 = 18. Percent decrease = (18 divided by 90) times 100 = 20%. The original value of 90 is used as the denominator, and 18 out of 90 equals exactly 20%. This confirms the statement is correct.

Explanation

The answer is True. Decrease = 90 minus 72 = 18. Percent decrease = (18 divided by 90) times 100 = 20%. The original value of 90 is used as the denominator, and 18 out of 90 equals exactly 20%. This confirms the statement is correct.

7) A car's value dropped from $25,000 to $20,000. What is the percent decrease?

15%

18%

20%

25%

Decrease = 25,000 minus 20,000 = $5,000. Percent decrease = (5,000 divided by 25,000) times 100 = 20%. Option A gives 15%, meaning a drop of $3,750. Option B gives 18%, meaning a drop of $4,500. Option D gives 25%, meaning a drop of $6,250. Only 20% matches the actual decrease of $5,000.

Explanation

Decrease = 25,000 minus 20,000 = $5,000. Percent decrease = (5,000 divided by 25,000) times 100 = 20%. Option A gives 15%, meaning a drop of $3,750. Option B gives 18%, meaning a drop of $4,500. Option D gives 25%, meaning a drop of $6,250. Only 20% matches the actual decrease of $5,000.

8) A $100 item decreases by 10% then another 20%. What is the final price?

$70

$72

$75

$76

After 10% off: 100 times 0.90 = $90. After 20% off the new price: 90 times 0.80 = $72. Option A gives $70, which would be a combined 30% off the original in one step. Option C gives $75, which does not match either calculation step. Option D gives $76, which has an error in one of the steps. Only $72 correctly applies both successive discounts.

Explanation

After 10% off: 100 times 0.90 = $90. After 20% off the new price: 90 times 0.80 = $72. Option A gives $70, which would be a combined 30% off the original in one step. Option C gives $75, which does not match either calculation step. Option D gives $76, which has an error in one of the steps. Only $72 correctly applies both successive discounts.

9) A store's revenue decreased from $2,400,000 to $1,920,000. What is the percent decrease?

15%

18%

20%

25%

Decrease = 2,400,000 minus 1,920,000 = $480,000. Percent decrease = (480,000 divided by 2,400,000) times 100 = 20%. Option A gives 15%, meaning a drop of $360,000. Option B gives 18%, meaning a drop of $432,000. Option D gives 25%, meaning a drop of $600,000. Only 20% matches the actual decrease.

Explanation

Decrease = 2,400,000 minus 1,920,000 = $480,000. Percent decrease = (480,000 divided by 2,400,000) times 100 = 20%. Option A gives 15%, meaning a drop of $360,000. Option B gives 18%, meaning a drop of $432,000. Option D gives 25%, meaning a drop of $600,000. Only 20% matches the actual decrease.

10) A population decreased from 80,000 to 64,000. What is the percent decrease?

15%

20%

25%

30%

Decrease = 80,000 minus 64,000 = 16,000. Percent decrease = (16,000 divided by 80,000) times 100 = 20%. Option A gives 15%, meaning a drop of 12,000. Option C gives 25%, meaning a drop of 20,000. Option D gives 30%, meaning a drop of 24,000. Only 20% matches the actual decrease of 16,000.

Explanation

Decrease = 80,000 minus 64,000 = 16,000. Percent decrease = (16,000 divided by 80,000) times 100 = 20%. Option A gives 15%, meaning a drop of 12,000. Option C gives 25%, meaning a drop of 20,000. Option D gives 30%, meaning a drop of 24,000. Only 20% matches the actual decrease of 16,000.

11) A laptop's price dropped from $900 to $720. What is the percent decrease?

15%

18%

20%

25%

Decrease = 900 minus 720 = $180. Percent decrease = (180 divided by 900) times 100 = 20%. Option A gives 15%, which would mean a drop of $135. Option B gives 18%, meaning a drop of $162. Option D gives 25%, meaning a drop of $225. Only 20% matches the actual decrease of $180.

Explanation

Decrease = 900 minus 720 = $180. Percent decrease = (180 divided by 900) times 100 = 20%. Option A gives 15%, which would mean a drop of $135. Option B gives 18%, meaning a drop of $162. Option D gives 25%, meaning a drop of $225. Only 20% matches the actual decrease of $180.

12) A 50% decrease followed by another 50% decrease equals a total decrease of 100%.

True

False

The answer is False. The second 50% is applied to the already-reduced amount, not the original. Starting with any value, say $100: after first 50% off = $50, after second 50% off = $25. The total decrease is $75 out of $100, which is 75%, not 100%. Successive percent decreases cannot be simply added together.

Explanation

The answer is False. The second 50% is applied to the already-reduced amount, not the original. Starting with any value, say $100: after first 50% off = $50, after second 50% off = $25. The total decrease is $75 out of $100, which is 75%, not 100%. Successive percent decreases cannot be simply added together.

13) A store reduced an $80 item by 40%, then reduced the new price by 25%. What is the final price?

$30

$32

$36

$40

After 40% off: 80 times 0.60 = $48. After 25% off the new price: 48 times 0.75 = $36. Option A gives $30, which would require a 62.5% total reduction. Option B gives $32, requiring 60% total. Option D gives $40, which is only the first discount applied incorrectly. Only $36 correctly applies both successive discounts.

Explanation

After 40% off: 80 times 0.60 = $48. After 25% off the new price: 48 times 0.75 = $36. Option A gives $30, which would require a 62.5% total reduction. Option B gives $32, requiring 60% total. Option D gives $40, which is only the first discount applied incorrectly. Only $36 correctly applies both successive discounts.

14) A laptop costs $1,200, discounted 25% then another 10% on the new price. What is the final price?

$810

$800

$900

$850

After 25% off: 1200 times 0.75 = $900. After 10% off the new price: 900 times 0.90 = $810. Option B gives $800, which would require a combined reduction greater than 33%. Option C gives $900, which is only after the first discount. Option D gives $850, which does not match either step of the calculation.

Explanation

After 25% off: 1200 times 0.75 = $900. After 10% off the new price: 900 times 0.90 = $810. Option B gives $800, which would require a combined reduction greater than 33%. Option C gives $900, which is only after the first discount. Option D gives $850, which does not match either step of the calculation.

15) A $500 phone decreases in price by 15%. What is the sale price?

$420

$425

$430

$440

15% of 500 = $75. Sale price = 500 minus 75 = $425. Option A gives $420, which would require a reduction of $80 or 16%. Option C gives $430, requiring a reduction of $70 or 14%. Option D gives $440, requiring a reduction of $60 or 12%. Only $425 correctly applies a 15% reduction.

Explanation

15% of 500 = $75. Sale price = 500 minus 75 = $425. Option A gives $420, which would require a reduction of $80 or 16%. Option C gives $430, requiring a reduction of $70 or 14%. Option D gives $440, requiring a reduction of $60 or 12%. Only $425 correctly applies a 15% reduction.

16) A coat cost $120 and now costs $96. What is the percent decrease?

16%

18%

20%

24%

Decrease = 120 minus 96 = $24. Percent decrease = (24 divided by 120) times 100 = 20%. Option A gives 16%, meaning a drop of $19.20. Option B gives 18%, meaning a drop of $21.60. Option D gives 24%, meaning a drop of $28.80. Only 20% matches the actual decrease of $24.

Explanation

Decrease = 120 minus 96 = $24. Percent decrease = (24 divided by 120) times 100 = 20%. Option A gives 16%, meaning a drop of $19.20. Option B gives 18%, meaning a drop of $21.60. Option D gives 24%, meaning a drop of $28.80. Only 20% matches the actual decrease of $24.

17) A decrease from $200 to $150 is a 25% decrease.

True

False

The answer is True. Decrease = 200 minus 150 = $50. Percent decrease = (50 divided by 200) times 100 = 25%. The original amount is always used as the denominator when computing percent decrease, and 50 out of 200 is exactly 25%.

Explanation

The answer is True. Decrease = 200 minus 150 = $50. Percent decrease = (50 divided by 200) times 100 = 25%. The original amount is always used as the denominator when computing percent decrease, and 50 out of 200 is exactly 25%.

18) A shirt originally costs $50 and is discounted by 30%. What is the new price?

$35

$40

$45.00

$30

30% of $50 = $15. New price = 50 minus 15 = $35. Option B gives $40, which is only a 20% discount. Option C gives $45, which is only a 10% discount. Option D gives $30, which would be a 40% discount. Only $35 correctly applies a 30% reduction to $50.

Explanation

30% of $50 = $15. New price = 50 minus 15 = $35. Option B gives $40, which is only a 20% discount. Option C gives $45, which is only a 10% discount. Option D gives $30, which would be a 40% discount. Only $35 correctly applies a 30% reduction to $50.

19) A city's population decreased from 100,000 to 85,000. What is the percent decrease?

10%

12%

20%

15%

Decrease = 100,000 minus 85,000 = 15,000. Percent decrease = (15,000 divided by 100,000) times 100 = 15%. Option A gives 10%, meaning a drop of 10,000. Option B gives 12%, meaning a drop of 12,000. Option C gives 20%, meaning a drop of 20,000. Only 15% matches the actual decrease of 15,000.

Explanation

Decrease = 100,000 minus 85,000 = 15,000. Percent decrease = (15,000 divided by 100,000) times 100 = 15%. Option A gives 10%, meaning a drop of 10,000. Option B gives 12%, meaning a drop of 12,000. Option C gives 20%, meaning a drop of 20,000. Only 15% matches the actual decrease of 15,000.

20) A jacket was $80 and is now $64. What is the percent decrease?

10%

15%

20%

25%

Decrease = 80 minus 64 = $16. Percent decrease = (16 divided by 80) times 100 = 20%. Option A gives 10%, meaning a drop of $8. Option B gives 15%, meaning a drop of $12. Option D gives 25%, meaning a drop of $20. Only 20% matches the actual decrease of $16.

Explanation

Decrease = 80 minus 64 = $16. Percent decrease = (16 divided by 80) times 100 = 20%. Option A gives 10%, meaning a drop of $8. Option B gives 15%, meaning a drop of $12. Option D gives 25%, meaning a drop of $20. Only 20% matches the actual decrease of $16.