Checkpoint 2 Spending & Simple Interest Lessons 6–10 30 min

Checkpoint 2 — Spending & Simple Interest

This checkpoint assesses your understanding of GST, best buys, payment plans, BNPL and simple interest. Calculators allowed. Show all working for short answer questions.

📝

Multiple Choice

01

Choose the correct answer

Foundation

1. What is the rate of GST in Australia?

A
5%
B
10%
C
15%
D
20%
Standard

2. Which of the following is a fixed expense?

A
Groceries
B
Entertainment
C
Monthly rent
D
Fuel for your car
Standard

3. A blender has a GST-exclusive price of $80. What is the GST-inclusive price?

A
$88
B
$85
C
$90
D
$92
Standard

4. A TV costs $1,200 cash. On hire purchase, the total cost is $1,440. How much extra does the buyer pay?

A
$120
B
$240
C
$440
D
$1,200
Standard

5. A $200 BNPL purchase is split into 4 payments. How much is each payment?

A
$40
B
$32
C
$50
D
$60
Standard

6. Calculate the simple interest on $5,000 at 4% p.a. for 3 years.

A
$500
B
$550
C
$650
D
$600
Standard

7. $3,000 is invested at 6% p.a. simple interest for 8 months. What is the interest earned?

A
$120
B
$180
C
$240
D
$1,440
Standard

8. A flat-rate loan of $10,000 at 7% p.a. for 4 years has total interest of:

A
$700
B
$2,800
C
$1,400
D
$12,800
Advanced

9. An investment earned $960 interest at 6% p.a. over 4 years. What was the principal?

A
$3,840
B
$5,760
C
$4,000
D
$6,000
Advanced

10. Which payment method typically does not charge interest?

A
Hire purchase
B
Credit card
C
Personal loan
D
Lay-by

Short Answer

02

Show your working

11. A supermarket sells rice in two sizes: 2 kg for $7.20 or 5 kg for $16.00.

(a) Calculate the unit price per kilogram for each size. (2 marks)
(b) Which is the better buy? (1 mark) 3 MARKS

12. A gaming console costs $600 cash. Three purchase options are available:

Option A: Cash payment of $600 today.
Option B: Lay-by with $100 deposit and $25/week for 20 weeks.
Option C: Hire purchase with $0 deposit and $30/week for 24 weeks.

(a) Calculate the total cost of each option. (3 marks)
(b) Which option is cheapest? By how much? (1 mark) 4 MARKS

13. A business borrows $12,000 at 7.5% p.a. simple interest for 18 months.

(a) Calculate the interest charged. (2 marks)
(b) Calculate the total amount to be repaid. (1 mark) 3 MARKS

14. A car dealership advertises: "$18,000 car, finance available at 5% p.a. flat rate, 5 years, only $375/month."

(a) Calculate the total interest paid over 5 years. (2 marks)
(b) Calculate the total amount paid for the car. (1 mark)
(c) Verify the monthly repayment by dividing the total by 60 months. (1 mark)
(d) Explain why this flat-rate loan is more expensive than a reducing-balance loan at the same advertised rate. (1 mark) 5 MARKS

✅ Answers

Multiple Choice

1. B — Australian GST is 10%

2. C — Monthly rent is a fixed expense

3. A — $80 × 1.10 = $88

4. B — $1,440 − $1,200 = $240 extra

5. C — $200 ÷ 4 = $50 per payment

6. D — I = $5,000 × 0.04 × 3 = $600

7. A — n = 8/12 = 2/3. I = $3,000 × 0.06 × (2/3) = $120

8. B — I = $10,000 × 0.07 × 4 = $2,800

9. C — P = $960 ÷ (0.06 × 4) = $960 ÷ 0.24 = $4,000

10. D — Lay-by does not charge interest

Short Answer

11 (3 marks): (a) 2 kg: $7.20 ÷ 2 = $3.60/kg [1]. 5 kg: $16.00 ÷ 5 = $3.20/kg [1]. (b) The 5 kg bag is the better buy [1].

12 (4 marks): (a) Option A: $600 [1]. Option B: $100 + ($25 × 20) = $600 [1]. Option C: $30 × 24 = $720 [1]. (b) Options A and B are both cheapest at $600. Option C is $120 more expensive [1].

13 (3 marks): (a) n = 18/12 = 1.5. I = $12,000 × 0.075 × 1.5 = $1,350 [2]. (b) Total = $12,000 + $1,350 = $13,350 [1].

14 (5 marks): (a) I = $18,000 × 0.05 × 5 = $4,500 [2]. (b) Total = $18,000 + $4,500 = $22,500 [1]. (c) $22,500 ÷ 60 = $375/month [1]. (d) Flat rate calculates interest on the full $18,000 for all 5 years, even as the balance is paid down. A reducing-balance loan would charge less interest over time because the owed amount decreases [1].