SmartPrep

O Level & A Level Mathematics (Cambridge)

O Level Mathematics — Number, Set 1

Take the O Level Mathematics — Number, Set 1: 20 multiple-choice questions (30 minutes) with instant scoring and a full answer review. Covers 20 O Level…

What this test covers

Sample questions with answers

The first 5 questions of this test, with the correct answer and explanation.

  1. Q1. What is the highest common factor (HCF) of 36 and 60?

    • A. 18
    • B. 6
    • C. 180
    • D. 12 ✓

    Answer: D. 12

    Explanation: 36 = 2² × 3² and 60 = 2² × 3 × 5; HCF = 2² × 3 = 12.

  2. Q2. What is the lowest common multiple (LCM) of 14 and 21?

    • A. 294
    • B. 84
    • C. 42 ✓
    • D. 7

    Answer: C. 42

    Explanation: 14 = 2 × 7 and 21 = 3 × 7; LCM = 2 × 3 × 7 = 42.

  3. Q3. Write 0.000452 in standard form.

    • A. 4.52 × 10⁻⁴ ✓
    • B. 45.2 × 10⁻⁵
    • C. 4.52 × 10⁻³
    • D. 4.52 × 10⁴

    Answer: A. 4.52 × 10⁻⁴

    Explanation: Move the decimal point 4 places right: 4.52 × 10⁻⁴.

  4. Q4. Calculate 3.7 × 10⁵ + 4 × 10⁴, giving the answer in standard form.

    • A. 7.7 × 10⁵
    • B. 4.1 × 10⁵ ✓
    • C. 7.7 × 10⁹
    • D. 4.1 × 10⁴

    Answer: B. 4.1 × 10⁵

    Explanation: 370 000 + 40 000 = 410 000 = 4.1 × 10⁵.

  5. Q5. Round 3.14159 to 3 significant figures.

    • A. 3.14 ✓
    • B. 3.15
    • C. 3.1
    • D. 3.141

    Answer: A. 3.14

    Explanation: Keep three significant figures: 3.14 (the next digit, 1, rounds down).

The other 15 questions

Take the timed test (free, no sign-up) to see your score and the answer and explanation for every question.

  1. Q6. Calculate 2/3 + 3/4.

    • A. 6/7
    • B. 17/12
    • C. 5/7
    • D. 5/12

  2. Q7. $120 is shared in the ratio 3 : 5. What is the larger share?

    • A. $80
    • B. $45
    • C. $75
    • D. $72

  3. Q8. What is 35% of 260?

    • A. 85
    • B. 169
    • C. 26
    • D. 91

  4. Q9. After a 20% increase, a price is $96. What was the original price?

    • A. $115.20
    • B. $76.80
    • C. $80
    • D. $76

  5. Q10. $2000 is invested at 5% per year compound interest. What is the value after 2 years?

    • A. $2200
    • B. $2210.50
    • C. $2205
    • D. $2100

  6. Q11. Simplify 2⁵ × 2⁻³.

    • A. 2⁻¹⁵
    • B. 8
    • C. 1/4
    • D. 4

  7. Q12. Evaluate 27^(−1/3).

    • A. 3
    • B. 1/3
    • C. −3
    • D. −1/3

  8. Q13. Write 0.454545… (recurring) as a fraction in its simplest form.

    • A. 9/20
    • B. 4/9
    • C. 45/100
    • D. 5/11

  9. Q14. A length is 12 cm, correct to the nearest centimetre. What is its upper bound?

    • A. 13 cm
    • B. 12.4 cm
    • C. 12.5 cm
    • D. 12.49 cm

  10. Q15. Write 180 as a product of prime factors.

    • A. 2³ × 3 × 5
    • B. 2 × 3 × 30
    • C. 2² × 45
    • D. 2² × 3² × 5

  11. Q16. Convert 72 km/h to metres per second.

    • A. 20 m/s
    • B. 72 m/s
    • C. 7.2 m/s
    • D. 259.2 m/s

  12. Q17. On a map with scale 1 : 50 000, two towns are 4 cm apart. How far apart are they in reality?

    • A. 12.5 km
    • B. 2 km
    • C. 20 km
    • D. 200 m

  13. Q18. If 1 US dollar = 280 Pakistani rupees, how many rupees is 50 dollars?

    • A. 14 000
    • B. 5 600
    • C. 1 400
    • D. 28 000

  14. Q19. Which one of these four numbers is irrational: √12, √16, 0.75 or 13/4?

    • A. 0.75
    • B. √12
    • C. 13/4
    • D. √16

  15. Q20. An item bought for $400 is sold for $500. What is the percentage profit?

    • A. 25%
    • B. 100%
    • C. 20%
    • D. 80%