Success TutoringWorksheets

Year 9 Simple and Compound Interest Worksheet — Level 3 — Practice Set 2 — Answers

Answer sheet with worked solutions for the Year 9 financial mathematics worksheet.

Download answers PDFPrint answersBack to worksheet
Success TutoringWorksheetsAnswer sheetYear 9 · Mathematics · Financial Mathematics

Year 9 Simple and Compound Interest Worksheet — Level 3 — Practice Set 2 — Answers

Show your working. Write the rate as a decimal (5% = 0.05). Round money to the nearest cent.

1.$14,750.00 is invested at 4.5% per year, compounded yearly, for 9 years. Find the final amount and the interest earned, to the nearest cent.

Answer: Amount $21,919.90; interest $7,169.90

  1. A = P(1 + r)n = $14,750.00 × (1 + 0.045)9
  2. = $14,750.00 × 1.486095
  3. ≈ $21,919.90
  4. Interest = $21,919.90 − $14,750.00 = $7,169.90
2.$12,500.00 is invested at 2% per year, compounded yearly, for 10 years. Find the final amount and the interest earned, to the nearest cent.

Answer: Amount $15,237.43; interest $2,737.43

  1. A = P(1 + r)n = $12,500.00 × (1 + 0.02)10
  2. = $12,500.00 × 1.218994
  3. ≈ $15,237.43
  4. Interest = $15,237.43 − $12,500.00 = $2,737.43
3.$2,750.00 is invested at 8% per year, compounded yearly, for 10 years. Find the final amount and the interest earned, to the nearest cent.

Answer: Amount $5,937.04; interest $3,187.04

  1. A = P(1 + r)n = $2,750.00 × (1 + 0.08)10
  2. = $2,750.00 × 2.158925
  3. ≈ $5,937.04
  4. Interest = $5,937.04 − $2,750.00 = $3,187.04
4.$4,250.00 is invested at 4% per year, compounded yearly, for 10 years. Find the final amount and the interest earned, to the nearest cent.

Answer: Amount $6,291.04; interest $2,041.04

  1. A = P(1 + r)n = $4,250.00 × (1 + 0.04)10
  2. = $4,250.00 × 1.480244
  3. ≈ $6,291.04
  4. Interest = $6,291.04 − $4,250.00 = $2,041.04
5.Compare $9,250.00 invested for 6 years at 2% per year as simple interest and as interest compounded yearly. How much more does compound interest earn, to the nearest cent?

Answer: $57.00

  1. Simple: I = $9,250.00 × 0.02 × 6 = $1,110.00
  2. Compound: A = $9,250.00 × 1.026 ≈ $10,417.00, so interest ≈ $1,167.00
  3. Difference = $1,167.00 − $1,110.00 = $57.00
6.Compare $6,250.00 invested for 10 years at 2.5% per year as simple interest and as interest compounded yearly. How much more does compound interest earn, to the nearest cent?

Answer: $188.03

  1. Simple: I = $6,250.00 × 0.025 × 10 = $1,562.50
  2. Compound: A = $6,250.00 × 1.02510 ≈ $8,000.53, so interest ≈ $1,750.53
  3. Difference = $1,750.53 − $1,562.50 = $188.03
7.$12,250.00 is invested at 4.5% per year, compounded yearly, for 8 years. Find the final amount and the interest earned, to the nearest cent.

Answer: Amount $17,420.73; interest $5,170.73

  1. A = P(1 + r)n = $12,250.00 × (1 + 0.045)8
  2. = $12,250.00 × 1.422101
  3. ≈ $17,420.73
  4. Interest = $17,420.73 − $12,250.00 = $5,170.73
8.$14,750.00 is invested at 6% per year, compounded yearly, for 3 years. Find the final amount and the interest earned, to the nearest cent.

Answer: Amount $17,567.49; interest $2,817.49

  1. A = P(1 + r)n = $14,750.00 × (1 + 0.06)3
  2. = $14,750.00 × 1.191016
  3. ≈ $17,567.49
  4. Interest = $17,567.49 − $14,750.00 = $2,817.49
Free worksheets at worksheets.successtutoring.com · © Success Tutoring · Free for personal and classroom use

Marking tips

  • Give credit for correct method even when the final answer slips — the working shows where the thinking went right.
  • For open-ended tasks, use the success criteria as a checklist rather than looking for one "right" answer.
  • Celebrate what went well first, then pick one thing to work on next.