O-Level Mathematics 1 — Questions and Answers
Question 1: Solve for x: 3x + 7 = 22
- 3
- 5 (Correct answer)
- 4
- 6
Correct answer: 5
3x = 22 - 7 = 15, so x = 15 ÷ 3 = 5.
Question 2: What is the value of 2³ × 4?
- 24
- 32 (Correct answer)
- 16
- 48
Correct answer: 32
2³ = 8, and 8 × 4 = 32.
Question 3: Factorise: x² - 9
- (x-3)(x-3)
- (x+3)(x-3) (Correct answer)
- (x+9)(x-1)
- (x-9)(x+1)
Correct answer: (x+3)(x-3)
x² - 9 is a difference of two squares: (x+3)(x-3).
Question 4: A rectangle has length 12 cm and width 5 cm. What is its area?
- 34 cm²
- 60 cm² (Correct answer)
- 17 cm²
- 70 cm²
Correct answer: 60 cm²
Area = length × width = 12 × 5 = 60 cm².
Question 5: What is 15% of 200?
- 25
- 30 (Correct answer)
- 35
- 20
Correct answer: 30
15% of 200 = (15/100) × 200 = 30.
Question 6: Simplify: (3x²y)(2xy³)
- 5x³y⁴
- 6x³y⁴ (Correct answer)
- 6x²y³
- 5x²y⁴
Correct answer: 6x³y⁴
Multiply coefficients: 3×2=6. Add exponents: x²·x=x³, y·y³=y⁴. Result: 6x³y⁴.
O-Level Mathematics 1
Solve for x: 3x + 7 = 22