Here are some formulas...
percent increase = (new number - original number) / original number...* 100
percent decrease = (original number - new number) / original number...* 100
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a student raises her grade from a 75 to a 90....since it is going from a smaller number to a larger number, u have an increase
percent increase = (90 - 75) / 70....* 100
= 15/70 * 100
= 0.2142 * 100
= 21.42 rounds to 21.4% increase
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36.50 on sale for 32.12...since it goes from a larger number to a smaller number, u have a decrease
percent decrease = (original number - new number) / original * 100
= (36.50 - 32.12) / 32.12...* 100
= 4.38 / 32.12...* 100
= 0.1363...* 100
= 13.63 rounds to 13.6% decrease
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23.5 to 21.2......this is a decrease
percent decrease = (original number - new number) / original...* 100
= (23.5 - 21.2) / 23.5....* 100
= 2.3 / 23.5....* 100
= 0.0979 * 100
= 9.79 rounds to 9.8% decrease
Let the number be x, then
1/5 * x = 2/3 * 90
1/5 x = 60
x = 60 * 5 = 300 (answer)
Multiply the amount in the account by the interest rate:
2500 x 0.034 = 85.00
Answer: $85.00
