SAT Math: Percent Increase and Decrease

A 25% increase multiplies by $1.25$ . A 20% decrease multiplies by $0.80$ .

Worked examples

$80 \times 1.25 = 100$

$0.80 p = 64$

$p = \frac{64}{0.80} = 80$

Finding the original price by adding 20% to the sale price.

$64 \times 1.20 = 76.80$ , not 80. The 20% was taken from the original price, so divide by $0.80$ .

A value of 60 increases by 15%. Find the new value.
Show answer
69
After a 30% discount, an item costs $49. Find the original price.
Show answer
$70
A value drops from 200 to 150. Find the percent decrease.
Show answer
25%

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