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Calculate simple interest and the cost of borrowing · Grade 9 · F1.3

Name: ______________________

Date: ______________________

1
Priya invests $700 at a simple interest rate of 8% per year for 2 years. How much interest does she earn?
Warm-up
Answer:
2
Priya invests $1000 at a simple interest rate of 3% per year for 1 years. How much interest does she earn?
Warm-up
Answer:
3
Priya invests $800 at a simple interest rate of 4% per year for 2 years. How much interest does she earn?
Warm-up
Answer:
4
Priya invests $1600 at a simple interest rate of 5% per year for 2 years. How much will she have in total?
On level
Answer:
5
Priya invests $300 at a simple interest rate of 7% per year for 1 years. How much will she have in total?
On level
Answer:
6
Priya invests $1600 at a simple interest rate of 6% per year for 3 years. How much will she have in total?
On level
Answer:
7
A car loan of $5000 is charged simple interest at 10% per year and repaid after 1 years. What is the total amount to repay?
Challenge
Answer:
8
A car loan of $9500 is charged simple interest at 7% per year and repaid after 5 years. What is the total amount to repay?
Challenge
Answer:
9
A car loan of $5500 is charged simple interest at 11% per year and repaid after 4 years. What is the total amount to repay?
Challenge
Answer:

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Worksheet code: eyJzIjoiZmluYW5jaWFsLXNpbXBsZS1pbnRlcmVzdCIsImQiOls5MzYwNzc2NTMsNDc4MTQxMDI5LDEzNjExMzUzNDgsOTM2NTA3MTI0LDE2NDIwMTU3NTcsMTA2NzkyOTI5OCw5NzYwNDgwNzIsNDAyMzM0NTAwLDY1MTE4OTI2OV0sInYiOjF9.9a8594fd0a46

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Answer key · Calculate simple interest and the cost of borrowing

1.
112 — I = P × r × t = $700 × 8% × 2 = $112.
2.
30 — I = P × r × t = $1000 × 3% × 1 = $30.
3.
64 — I = P × r × t = $800 × 4% × 2 = $64.
4.
1760 — Interest = $160; total = $1600 + $160 = $1760.
5.
321 — Interest = $21; total = $300 + $21 = $321.
6.
1888 — Interest = $288; total = $1600 + $288 = $1888.
7.
5500 — Interest = $5000 × 10% × 1 = $500; total to repay = $5000 + $500 = $5500.
8.
12825 — Interest = $9500 × 7% × 5 = $3325; total to repay = $9500 + $3325 = $12825.
9.
7920 — Interest = $5500 × 11% × 4 = $2420; total to repay = $5500 + $2420 = $7920.