S3 7.1-Ch7 Percentage(II)

If the toll rate of a tunnel changes from $24 to $30, then the percentage change in the toll rate is

• –25%.

• –20%.

• +20%.

• +25%.

The side of a cube decreases by 20%. Find the percentage change in its volume.

• –32%

• –48.8%

• –51.2%

• –64% 

The number of customers of a shop was 625 two weeks ago. The number of customers increased by 8% last week and then further increased by 12% this week. Find the number of customers of the shop this week.

• 526

• 750

• 756

• 1260

       If the monthly salary of Ada is 10% higher than that of Belly and the monthly salary of Belly is 10% lower than that of Cindy, then

• the monthly salary of Ada is 1% higher than that of Cindy.

• the monthly salary of Ada is 1% lower than that of Cindy.

• the monthly salary of Cindy is 1% higher than that of Ada.

• the monthly salary of Cindy is 1% lower than that of Ada. 

The width of a rectangle increases by 60%. If the area of the rectangle remains unchanged, then the percentage change in its length is

• –37.5%.

• –40%.

• –60%.

• –62.5%. 

The ratio of Michelle’s monthly expenditure on food, transport and rent is 3 : 3 : 4. If the expenditure on food decreases by 5%, the expenditure on transport increases by 8% and the expenditure on rent increases by 6%, find the percentage change in the monthly expenditure.

• +3%

• +3.3%

• +8.756%

• +9%