Repeated percentage change

What percentage change is equivalent to:

an increase of 7% followed by a decrease of 7%?

• 0.49% decrease

• 0.49 increase

• 7% decrease

• No change

What percentage change is equivalent to:

an increase of 15% followed by another increase of 20%.

• 38% increase

• 35% increase

• 30% increase

• 5% increase

What percentage change is equivalent to:

a decrease of 20% followed by another decrease of 35%.

• 55% percent decrease

• 15% decrease

• 40% decrease

• 48% decrease

Li bought a new car for $23 000. After one year the car had decreased in value by 20%. In the following year, the car decreased in value by a further 17%.

Calculate the value of the car after two years.

• $18400

• $15272

• $14490

• $13336

An electronics store increased the prices of all laptops by 8%. During the end of year sales, all stock was discounted by 10%. A laptop originally cost $995.

What was the new price of the laptop after the price increase?

• 1024.60

• 1044.60

• 1074.60

• 1084.60

An electronics store increased the prices of all laptops by 8%. During the end of year sales, all stock was discounted by 10%. A laptop originally cost $995.

What is the price of the laptop during the end of year sales?

• 867.14

• 917.14

• 947.14

• 967.14

Cafe X increased all prices by 10% but then offered a 5% discount to all customers with a Cafe X loyalty card. Before the prices were changed, a coffee cost $4.50. Following the price increase, how much would a coffee cost for a customer with a loyalty card?

• $4.50

• $4.60

• $4.70

• $4.80

Marco went on a weight-loss diet. Initially, his weight was 92.5 kg. In the first month, he reduced his weight by 1.7%. In the second month, his weight decreased by 2.9%.

What was Marco’s weight after two months of dieting? Answer to one decimal place.

• 91.5

• 90.4

• 89.6

• 88.3

After months of rain, the Clareville dam was full. Over the next year, the amount of water in the dam decreased by 16%. The following year it increased by 5%. What was the overall percentage change in the amount of water in Clareville dam?

• 11.8% decrease

• 11% decrease

• 8% decrease

• 8.8% decrease

At an intersection on a busy road, the number of accidents in 2010 was 35. In 2011 this increased by 20%.

At the start of 2012, a set of traffic lights was put in at the intersection and the number of accidents decreased by 69%.

How many accidents were there at the intersection in 2012? Answer to the nearest whole number.

• 7

• 9

• 11

• 13