Simple Interest and Percent Change

Simple Interest and Percent Change

Simple Interest = Principal x Rate(% per year) x Time (in years)

1. Find the simple interest and the final amount.

a. $400 for 2 years @ 4% p.a. b. $8000 for 3 months at 7.25% p.a.

c. $280 for 5 years and 3 months at 2.5% p.a. d. $575 for 124 days at 12.5% p.a.

2. Mr. Leonard put in a certain amount of money at 5.25% p.a. for 1 year and received $56 in interest. How much did he put in the bank?

3. In how many years will $500 yield $140 in simple interest at 7% p.a.?

4. At what rate p.a. will $350 amount to $455 in 5 years? (assume simple interest)

% change = %

1. Find the Percent change if a quantity changes from:

a. 60 to 48 b. 2 to 7 c. to d. 0.25 to 0.3

e. 8% to 7.5% f. 25% to 90% g. 8.7mL to 10mL h. 25¢ to $26.5

2. The price of a car decreases by 12% a year. What will the price of a $34500 Dodge Ram be after 2 years?

3. The price of a house has increased by 3% since last year. If it cost $200 000 now, what was the worth of the house last year?

4. According to the CPI (consumer price index), a $19 item from 1950 cost $119.5 in 1990,

a. find the percent increase. b. find the price of a $2 1950 pen in 1990.

c. find the cost of a $100 1990 jacket back in 1950.

REVIEW I

1. Express as a percent.

a. b. c. d. 5.2

e. 0.054 f. 0. g. 8 h. 1

2. Express as a fraction in lowest terms.

a. 56.3% b. 0.025% c. 33% d. 125%

3. Find the unknown.

a. 4.5% of 240g b. 75% of 200m c. 8% of $51000 d. 160 is 80% of n

e. 4% of n is 5. f. n% of 45 is 54. g. 12.5% of n is 2 h. n% of 3 is 1.75

4. A man sells a carpet for $700 and gains 12% profit. What is the carpet at cost?

5. Will buys a tennis racket for $35 and sells it for $40. What is his % profit?

6. How much do I pay for a $39.99 plus GST on a pair of shoes if the discount is at 5%?

7. Find the simple interest on a $2000 loan at 6% p.a. for 1 year 4 months.

8. $960 @ 5% per month for n years will amount to $2112. What is n?

9. The sum of 20% and 40% of a number is 54. What is the number?

10. Lily bought a jacket for $48 at a discount of 15%. Find the original price.

11. Bob gets 7.5% commission on any sales over $25000, how much does he get for a total sale of $40000?

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REVIEW II

1. Express each as percentages.

a. 35 out of 80 b. 80cm out of 2m c. 800min out of 1hr. d. 40¢ out of $1.25

2. Find the values.

a. 42.5% of $250 b. 66% of 100L c. 125% of 240 bottles d. 37% of 28kg

e. n% of 4 is 2 f. n% of 12 is 5 g. n% of 16 is 4 h. n% of 3is 7

i. 2% of what is 5 j. 4% of n is 13 k. 5.25% of n is $1200 l. 2% of n is 0.15

3. Express the following rates in the given units.

a. 4kg of rice cost $23 ($/kg) b. 6 boxes of truffles cost $125. ($/box)

c. 175km in 1.5h (km/h) d. 2.3cm in 3.5h (cm/h)

4. A train travels 75km in 45 minutes.

a. find its speed in km/h b. how far will it travel in 1 hr. 20min?

c. how long will it take to travel 1 km? d. how long will it take to travel 350km?

5. Write the ratios in lowest terms.

a. 25:45 b. 2: c. 75g:0.25kg d. 2.4:1.05

6. If a:b = 4:5 and b:c = 3:7, find a:b:c

7. $3500 is divided into a ratio of 2:3:1. Find the amount for each part.

8. 3 parts of yellow is mixed with 5 parts of blue to make green. Find the amount of each to make 24L of green paint.

9. A, B and C share a bag of chips in the ratio of 2:7:9. If C gets 27 pieces of chips, how many pieces of chips in total are there in the bag to begin with?

10. The cost of painting a square ceiling of side 5m is $65. Find the cost of painting a square ceiling of side 10m.

11. Find unknown.

a. n:20 = 4:5 b. 15:n=3:4 c. 4.5:7 = 6:n d. 5.6: 4.3 = n:7