Lesson 28 Section 2 ## Percent increase or decreaseExample 1. A blouse that usually sells for $32 is on sale at 25% off. How much do you pay?
Example 2. A VCR that usually sells for $180 is being sold at a
taken off. A third of 180 is 60. (Lesson 16, Question 1.) You will pay $180 − $60 = $120. Example 3. A CD that last week sold for $15 now costs 10% more. How much does it cost now?
$15 + $1 Example 4. A store increased the price of an item by 25%. By what percent must it decrease the new price in order to restore the original?
Let this figure, then, represent the original price divided into quarters. In this figure, it is increased by a quarter. The whole is now in Here is the sequence of names of the parts. Half, third, fourth, fifth, sixth. And so on. In any problem of this type, by whichever part the original price was increased, the new price must be reduced by the next part in the sequence. If the price was increased by a third, then to restore the original, the new price must be reduced by a fourth. If increased by a fourth, it must be reduced by a fifth. And so on. See Problem 13 . Example 5 Calculator problem. An item costs $39.95, and the tax
That is, press the + key. Do not press = . See
You will pay $43.45. Alternatively, the total cost is 100% of the item plus 8.75%, which is a total of 108.75%. Press
Example 6. Calculator problem Marlene's rent was $672.50. It was reduced by 6½%. What is her present rent?
See
Her present rent is $628.79. Estimations When using a calculator, and in general, the student should have some idea as to where the answer lies. With a calculator it is very easy to press a wrong button. Example 7. How much is 26 $
Example 8. How much is 49 $1,020 $102 $10
Example 9. 98 is approximately what percent of 204? 16% 48% 52% 89%
Example 10. What percent of 40 is 11? 6% 24% 27% 9%
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