Answers − Percentage Change
1. The original price is 500 and the new price is 700.
Find the percentage increase
| (a) the increase amount is 700 − 500 = 200 |
| (b) the percentage as a fraction is 200/500 = 2/5 |
| (c) 100 ÷ 5 = 20 (where 5 is the demoninator of the fraction) |
| (d) 2/5 × 20/20 = 40/100 = 40% |
| So 40% increase in price |
2. The original price is 470 and the new price is 564.
Find the percentage increase
| (a) the increase amount is 564 − 470 = 94 |
| (b) the percentage as a fraction is 94/470 = 1/5 |
| (c) 100 ÷ 5 = 20 (where 5 is the demoninator of the fraction) |
| (d) 1/5 × 20/20 = 20/100 = 20% |
| So 20% increase in price |
3. The original price is 50 and the new price is 40.
Find the percentage decrease
| (a) the decrease amount is 50 − 40 = 10 |
| (b) the percentage as a fraction is 10/50 = 1/5 |
| (c) 100 ÷ 5 = 20 (where 5 is the demoninator of the fraction) |
| (d) 1/5 × 20/20 = 20/100 = 20% |
| So 20% decrease in value. |
4. The original price is 1100 and the new price is 990.
Find the percentage decrease
| (a) the decrease amount is 1100 − 990 = 110 |
| (b) the percentage as a fraction is 110/1100 = 1/10 |
| (c) 100 ÷ 10 = 10 (where 10 is the demoninator of the fraction) |
| (d) 1/10 × 10/10 = 10/100 = 10% |
| So 10% decrease in value. |
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