A wheel has a diameter of 70 cm. It turns 50 complete times along a straight path. How far does it travel? Give your answer in metres. (Take π = 227)
Need a hint?
In one turn, the wheel travels one circumference.
Worked answer
- One turn = circumference = 22/7 × 70 = 220 cm.
- 50 turns = 50 × 220 = 11 000 cm.
- 11 000 cm = 110 m.
Answer: 110 m
The mistake this question tests
Habit
Radius and diameter in circles
The circumference uses the diameter, 70 cm, as it is. Doubling it, or halving it, gives the wrong distance.
How to fix it at home →Wrong answers children often give:
- 55 Radius and diameter in circles
- 220 Radius and diameter in circles
- 11000 Converting units (kg, ℓ, m, cm³)
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