Percentage Increase or Decrease

A car dealer buys a car for $500 and then sells it for $640. What is the percentage profit?

A damaged carpet which costs $180 when new, is sold for $100. What is the percentage loss? Answer in 3 s.f.

During the first 4 weeks of her life, a baby girl increases her mass from 3.2 kg to 4.7 kg. What percentage increase does this represent? (Give your answer to 3 s.f.)

When tax is added to the cost of a lipstick, its price increases from $16.50 to $18.48. What is the rate at which tax is charged?

The price of a sports car is reduced from $30 000 to $28 400. What percentage reduction is this? Answer in 3 s.f.

A pair of jeans is sold for $15, thereby making a profit of 25% on the cost price. What was the cost price?

A can of worms is sold for 48c, incurring a loss of 20%. What was the cost price?

If an employer reduces the working week from 40 hours to 35 hours, with no loss of weekly pay, calculate the percentage increase in the hourly rate of pay. (Answer in 3 s.f.)

The rental for a television set changed from $80 per year to $8 per month. What is the percentage increase in the yearly rental?

Given G = ab, find the percentage increase in G when both a and b increase by 10%