GCSE GCSE Mathematics 2 — Questions and Answers
Question 1: What is the sum of interior angles of a pentagon?
- 360°
- 450°
- 540° (Correct answer)
- 720°
Correct answer: 540°
The sum of interior angles of a polygon = (n − 2) × 180°, where n is the number of sides. For a pentagon: (5 − 2) × 180° = 3 × 180° = 540°.
Question 2: A car is bought for £8,000 and depreciates by 20% in the first year. What is its value after one year?
- £1,600
- £6,000
- £6,400 (Correct answer)
- £7,800
Correct answer: £6,400
20% of £8,000 = £1,600. Value after depreciation = £8,000 − £1,600 = £6,400. Alternatively: 80% × £8,000 = 0.8 × £8,000 = £6,400.
Question 3: Solve the simultaneous equations: x + y = 7 and x − y = 3
- x = 5, y = 2 (Correct answer)
- x = 4, y = 3
- x = 3, y = 4
- x = 6, y = 1
Correct answer: x = 5, y = 2
Add the equations: 2x = 10, so x = 5. Substitute: 5 + y = 7, so y = 2. Check: 5 − 2 = 3 ✓.
Question 4: What is the Pythagorean theorem?
- a + b = c
- a² + b² = c² (Correct answer)
- a² − b² = c²
- (a + b)² = c
Correct answer: a² + b² = c²
The Pythagorean theorem states that in a right-angled triangle, the square of the hypotenuse (c, the longest side) equals the sum of the squares of the other two sides: a² + b² = c².
Question 5: Write 0.000325 in standard form.
- 3.25 × 10⁻⁴ (Correct answer)
- 3.25 × 10⁴
- 32.5 × 10⁻⁵
- 0.325 × 10⁻³
Correct answer: 3.25 × 10⁻⁴
Standard form is a × 10ⁿ where 1 ≤ a < 10. Move the decimal point 4 places to the right to get 3.25, so 0.000325 = 3.25 × 10⁻⁴.
Question 6: The bearing from A to B is 065°. What is the bearing from B to A?
- 245° (Correct answer)
- 115°
- 295°
- 125°
Correct answer: 245°
To find the back-bearing, add 180° to the original bearing. 065° + 180° = 245°. Back-bearings always differ by 180°.
GCSE GCSE Mathematics 2
What is the sum of interior angles of a pentagon?