Chapter 5

• Mathematics
• Secondary Education

Increase 40 by 15%

1. 45
2. 46
3. 47
4. 48

Increase 124 by 200%

Decrease 36.2 by 15%

Decrease 20 by %

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Shajeen usually works 30 hours per week but decides that he needs to increase this by 10% to be sure that he can save enough for a holiday. How many hours per week will Shajeen need to work?

12% sales tax is applied to all items of clothing sold in a certain shop. If a T-shirt is advertised for $12(before tax) what will be the cost of the T-shirt once the tax is added?

The Oyler Theatre steps up its advertising campaign and manages to increase its audiences by 23% during the year. If 21 300 people watched plays at the Oyler Theatre during the previous year, how many people watched plays in the year of the campaign?

The population of Trigville was 153 000 at the end of the year. Following a flood, 17% of the residents moved away.
What was the population of Trigville after the flood?

Anthea decides that she is watching too much television. If Anthea watched 12 hours of television in a week and then decrease this by 12% of the next week, how much time did Anthea spend watching television in the second week? Give your answer in hours and minutes to the nearest minute.

Reverse Percentages

Reverse Percentages

If 20% of an amount is 35, what is 100%

Seven students were absent from a class on Monday. This is 17.5% of the class.
a. How many students are there in the class in total?
b. How many students were present on Monday?

A hat shop is holding a 10% sale. If Jack buys a hat for $18 in the sale, how much did the hat cost before the sale?

Nick is training for a swimming race and reduces his weight by 5% over a 3-month period. If Nick now weighs 76 kg how much did he weigh before he started training?

STANDARD FORM

STANDARD FORM

Write each number in standard form.
a. 4 200 000 b. 10.3
c. 5 d. 0.00025

ESTIMATE

With a calculator