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Percentage increase and decrease

Apply percentage increase and decrease to find new values, and use reverse percentage to find the original amount.

Worked examples

Increasing a value by a percentage

Straightforward

Problem

Increase $150\$150 by 20%20\%.

Percentage decrease in context

Moderate

Problem

A laptop costs $1,200\$1{,}200. A store reduces the price by 15%15\% for a sale. Find the sale price.

Finding the original price (reverse percentage)

Challenging

Problem

After a 25%25\% discount, a bag costs $90\$90. Find the original price.

Practise

Q1·Straightforward
Increase $80\$80 by 15%15\%. What is the new amount (in dollars)?
Q2·Straightforward
Decrease $200\$200 by 10%10\%. What is the new amount (in dollars)?
Q3·Straightforward
A bag of sand weighs 450450 kg. Its weight increases by 20%20\%. What is the new weight (in kg)?
Q4·Straightforward
Decrease $75\$75 by 40%40\%. What is the new amount (in dollars)?
Q5·Moderate
A worker earns $52,000\$52{,}000 per year. Their salary increases by 5%5\%. What is their new annual salary (in dollars)?
Q6·Moderate
A television is priced at $840\$840. It is reduced by 25%25\% in a sale. What is the sale price (in dollars)?
Q7·Moderate
A town has a population of 12,40012{,}400. The population increases by 8%8\% over one year. What is the new population?
Q8·Moderate
A jacket has a marked price of $180\$180. A store reduces its price by 35%35\%. What is the new price (in dollars)?
Q9·Challenging
After a 20%20\% discount, a pair of shoes costs $48\$48. What was the original price (in dollars)?
Q10·Challenging
After a 15%15\% price increase, an item costs $115\$115. What was the original price (in dollars)?
Q11·Challenging
After a 12%12\% price rise, a service costs $280\$280. What was the original price (in dollars)?
Q12·Challenging
A coat is reduced by 30%30\% and sells for $63\$63. What was the original price (in dollars)?