11+ Mathematics Problem Solving 4 — Questions and Answers
Question 1: What is the sum of all interior angles in a hexagon?
- 540°
- 720° (Correct answer)
- 360°
- 900°
Correct answer: 720°
Sum of interior angles = (n - 2) × 180° = (6 - 2) × 180° = 4 × 180° = 720°.
Question 2: A school has 450 pupils. 2/5 are boys. How many girls are there?
- 180
- 270 (Correct answer)
- 225
- 300
Correct answer: 270
Boys = 2/5 × 450 = 180. Girls = 450 - 180 = 270.
Question 3: Express 7/20 as a percentage.
- 30%
- 35% (Correct answer)
- 37%
- 40%
Correct answer: 35%
7/20 = 7 × 5 / (20 × 5) = 35/100 = 35%.
Question 4: A water tank holds 350 litres. It is 3/7 full. How many more litres are needed to fill it?
- 150 litres
- 200 litres (Correct answer)
- 250 litres
- 100 litres
Correct answer: 200 litres
Currently has 3/7 × 350 = 150 litres. Remaining = 350 - 150 = 200 litres needed.
Question 5: What are the coordinates of the midpoint between (2, 8) and (10, 4)?
- (6, 6) (Correct answer)
- (8, 6)
- (5, 7)
- (6, 4)
Correct answer: (6, 6)
Midpoint = ((2+10)/2, (8+4)/2) = (12/2, 12/2) = (6, 6).
Question 6: A number is increased by 25% to give 90. What was the original number?
- 67.5
- 72 (Correct answer)
- 75
- 80
Correct answer: 72
Original × 1.25 = 90. Original = 90 ÷ 1.25 = 72.
11+ Mathematics Problem Solving 4
What is the sum of all interior angles in a hexagon?