1. Alex reads 400 out of 650 pages; what percent is left? (round to the tenth)
2. Alex wanted to buy his mom a famous painting for $100,000, but he had a coupon for 15% off, and then also enjoyed another 3% discount because he paid in cash...what did he pay?
3. Alex earned $75,000 last month. This month, his salary increased by 12%, what did he make this month?
Find the number in each case.
a) 48% of a number is 12. f) 48% of 25.
b) 12 is what percent of 25 g) 9 is 15% of a number.
c) 15% of 60. f) 9 is what percent of 60
d) 160% of 60 i) 96 is what percent of 60
e) 96 is 160% of a number
4. An item used to sell for seventy-five cents a pound, and you see that it's been marked up to eighty-one cents a pound. What is the percent increase?
5. The population of Alberta was 3,433,145 in 2008 and 3,520,268 in 2009. Was this an
increase or a decrease and calculate the percent?
6. The population of Alberta was 1,265,572 in 1960. If the population was 3,520,268 in 2009, by what percent did this increase or decrease?
7. The population of walleye in a lake is estimated to be 12 345 at the end of the year and 13 624 at the beginning of the year. By what percent did this increase or decrease?
8 The number of employees at a company went from 7623 to 6824. By what percent did this increase or decrease?
9. Find the percentage change from the first quantity to the second quantity:
(i) $75; $90
(ii) 40 cm; 60 cm
(iii) 20 gm; 5 gm
(iv) 60 km/h; 45 km/h
(v) 5 dozen eggs; 100 eggs
(vi) 13.5; 18
10. Increase 150 by 10 % and decrease the same by 15 %. Find the new number in each case.
11. The population of a place in a particular year increased by 15 %. Next year it decreased by 15%. Find the net increase or decrease per cent in the initial population.
12. While measuring a line segment of length 5 cm, it was measured 5.2 cm by mistake. Find the percentage error in measuring the line segment.
13. A number is increased by 40 % and then decreased by 40 %. Find the net increase or decrease per cent.
14. The price of wheat increased by 10 %. By how much per cent should mother reduce her consumption in the house so that her expenditure on wheat does not increase?
15. The salary of a doctor is increased by 40 %. By what per cent should the new salary be reduced in order to restore the original salary?
16. A number 75 is misread as 57. Find the reading error per cent.
answers:
9. (i) 20 % increase
(ii) 50 % increase
(iii) 75 % decrease
(iv) 25 % decrease
(v) 662/3 % increase
(vi) 331/3 % increase
10. 165, 127.5
11. 2.25 % decreased
12. 4 %
13. 16 %
14. 91/11 %
15. 284/7 %
16. 24 %