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4024/21 Oct/Nov 2022, Question 1: Dividing in a Given Ratio

Cambridge O Level Mathematics 4024 · Paper 21 (Calculator) · Calculator · 12 marks

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The question, in short

Abid's working week, pay rise, spending ratio, simple interest rate and compound interest investment are worked out across five parts.

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

Part (a) · 2 marks

Find Abid's total weekly working time in hours and minutes from his daily start and finish times over 5 days.

  1. 108 15 to 12 40 = 4 h 25 min
  2. 213 30 to 17 00 = 3 h 30 min
  3. 3One day = 7 h 55 min = 475 min
  4. 45 days = 5 × 475 = 2375 min
  5. 5= 39 hours 35 minutes

Answer39 hours 35 minutes

Part (b) · 2 marks

Calculate Abid's new hourly pay after a 5% increase on $14.20 per hour.

  1. 15% of 14.20 = 5/100 × 14.20 = 0.71
  2. 214.20 + 0.71 = $14.91

Answer14.91

Part (c) · 3 marks

With 20% for rent and 3/8 for bills, find the rent : bills : savings ratio in simplest form.

  1. 1Rent = 20%, bills = 3/8 = 37.5%
  2. 2Savings = 100 − 20 − 37.5 = 42.5%
  3. 320 : 37.5 : 42.5 = 40 : 75 : 85
  4. 4= 8 : 15 : 17

Answer8 : 15 : 17

Part (d) · 2 marks

Given $2400 invested for 4 years earning $153.60 simple interest, calculate the annual rate r.

  1. 1(2400 × r × 4)/100 = 153.60
  2. 296r = 153.60
  3. 3r = 1.6

Answer1.6

Part (e) · 3 marks

Find the amount invested if it grows at 1.4% compound interest per year to $1822.38 after 5 years.

  1. 1x × (1 + 1.4/100)⁵ = 1822.38
  2. 2x = 1822.38 ÷ 1.014⁵
  3. 3= $1700.00

Answer1700.00

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Also searched as: 4024/21/O/N/22 · 4024_w22_qp_21 · 4024 w22 21 · question 1.
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