O-Level Mathematics 2

Question 1

The mean of five numbers is 8. Four of the numbers are 6, 9, 7, and 10. What is the fifth number?

Accepted Answer

8

Answer

Sum = 8 × 5 = 40. Known sum = 6+9+7+10 = 32. Fifth number = 40 - 32 = 8.

Question 2

What is the gradient of the line passing through (2, 3) and (6, 11)?

Accepted Answer

2

Answer

Gradient = (11-3)/(6-2) = 8/4 = 2.

Question 3

Solve: 2x - 3 = x + 5

Accepted Answer

8

Answer

2x - x = 5 + 3, so x = 8.

Question 4

A cylinder has radius 7 cm and height 10 cm. What is its volume? (Use π ≈ 22/7)

Accepted Answer

1540 cm³

Answer

Volume = πr²h = (22/7) × 49 × 10 = 22 × 7 × 10 = 1540 cm³.

Question 5

Express 0.000045 in standard form.

Accepted Answer

4.5 × 10⁻⁵

Answer

0.000045 = 4.5 × 10⁻⁵ (move decimal 5 places to the right).

GCE O-Level Practice Test