Percent of a number, and percent increase or decrease
Understand and recall common percent-fraction-decimal equivalents, and use mental math to increase or decrease a number by a percent. Unlimited questions, five difficulty levels, and a full worked solution every time — free.
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What is 15% of 120?
Answer: 18
See one solved, step by step
A monthly bus pass costs $30.00. The price increases by 15%. What is the new price?
📘 Worked solution
115% of $30.00 = 0.15 · 30 = 4.5Convert 15% to a decimal and multiply by the price.
2$30.00 + 4.5 = 34.5An increase means adding the change on top of the original amount.
3New amount: $34.50Round money to two decimal places.
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