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

Name: ______________________

Date: ______________________

1
Priya invests $500 at a simple interest rate of 1% per year for 4 years. How much interest does she earn?
Warm-up
Answer:
2
Priya invests $1200 at a simple interest rate of 3% per year for 1 years. How much interest does she earn?
Warm-up
Answer:
3
Priya invests $1500 at a simple interest rate of 3% per year for 4 years. How much interest does she earn?
Warm-up
Answer:
4
Priya invests $1000 at a simple interest rate of 2% per year for 4 years. How much will she have in total?
On level
Answer:
5
Priya invests $700 at a simple interest rate of 7% per year for 5 years. How much will she have in total?
On level
Answer:
6
Priya invests $100 at a simple interest rate of 5% per year for 4 years. How much will she have in total?
On level
Answer:
7
A car loan of $3000 is charged simple interest at 5% per year and repaid after 3 years. What is the total amount to repay?
Challenge
Answer:
8
A car loan of $8500 is charged simple interest at 5% per year and repaid after 2 years. What is the total amount to repay?
Challenge
Answer:
9
A car loan of $5000 is charged simple interest at 10% per year and repaid after 4 years. What is the total amount to repay?
Challenge
Answer:

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Worksheet code: eyJzIjoiZmluYW5jaWFsLXNpbXBsZS1pbnRlcmVzdCIsImQiOlsxMDg3NTk3NDg2LDE2NzUzMjc2MDQsMTIwNDU0MjkyMCw2MTU2Njg3MzYsNzgzNDEzNDAzLDIxNDUzMDI3NjIsMTg4ODkxNTUyMywyMDg3OTU4NzU3LDEzNjk3MjIwNDFdLCJ2IjoxfQ.551e05ac7648

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Answer key · Calculate simple interest and the cost of borrowing

1.
20 — I = P × r × t = $500 × 1% × 4 = $20.
2.
36 — I = P × r × t = $1200 × 3% × 1 = $36.
3.
180 — I = P × r × t = $1500 × 3% × 4 = $180.
4.
1080 — Interest = $80; total = $1000 + $80 = $1080.
5.
945 — Interest = $245; total = $700 + $245 = $945.
6.
120 — Interest = $20; total = $100 + $20 = $120.
7.
3450 — Interest = $3000 × 5% × 3 = $450; total to repay = $3000 + $450 = $3450.
8.
9350 — Interest = $8500 × 5% × 2 = $850; total to repay = $8500 + $850 = $9350.
9.
7000 — Interest = $5000 × 10% × 4 = $2000; total to repay = $5000 + $2000 = $7000.