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4024/21 Oct/Nov 2024, Question 1: Currency Conversions

Cambridge O Level Mathematics 4024 · Paper 21 (Calculator) · Calculator · 11 marks

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The question, in short

Toy shop problem: find weekly opening time, a supervisor's hourly pay, a game's selling price in dollars, and the money left in a compound interest account after withdrawals.

Summarised in our own words. Use the official paper for the exact wording and any diagrams.

Part (a) · 1 mark

Using the two opening-hour rows, work out the total time the shop is open during one week.

  1. 1Saturday to Wednesday: 18 00 − 10 30 = 7.5 hours × 5 days = 37.5 hours
  2. 2Thursday and Friday: 19 30 − 10 00 = 9.5 hours × 2 days = 19 hours
  3. 3Total = 37.5 + 19 = 56.5 hours

Answer56.5

Part (b) · 3 marks

Given 5 assistants at 30 hours and $13.45 per hour, 2 supervisors at 38 hours, and $3324.70 total, find each supervisor's hourly pay.

  1. 1Sales assistants: 5 × 30 × 13.45 = $2017.50
  2. 2Supervisors get 3324.70 − 2017.50 = $1307.20
  3. 3Per hour = 1307.20 ÷ (2 × 38) = 1307.20 ÷ 76
  4. 4= $17.20

Answer17.20

Part (c) · 4 marks

With $1 = £0.77, 50 games costing £245 total and 39% profit per game, find one game's selling price in dollars to the nearest cent.

  1. 1Cost of one game = 245 ÷ 50 = £4.90
  2. 2In dollars: 4.90 ÷ 0.77 = $6.3636…
  3. 3Selling price = 6.3636… × 1.39 = 8.845…
  4. 4= $8.85

Answer8.85

Part (d) · 3 marks

Starting with $12000 at 1.5% compound interest, adding $12000 after year 1 and removing $20000 after year 4, find the remaining amount to the nearest cent.

  1. 1First $12 000 for 4 years: 12000 × 1.015⁴ = 12 736.36…
  2. 2Second $12 000 for 3 years: 12000 × 1.015³ = 12 548.14…
  3. 3Total = 25 284.50…
  4. 4Remaining = 25 284.50 − 20 000 = $5284.50

Answer5284.50

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Also searched as: 4024/21/O/N/24 · 4024_w24_qp_21 · 4024 w24 21 · question 1.
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