A cycle wheel has radius 28 cm. What percentage of its circumference is covered in one-fifth of a turn? (Use π = 22/7)
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 20%.
Circumference = 2 × π × r
Circumference = 2 × 22/7 × 28
= 44/7 × 28 = 176 cm
One-fifth of a turn covers = 1/5 × 176 = 176 ÷ 5 = 35.2 cm
Percentage of circumference = (35.2 ÷ 176) × 100
= 0.2 × 100 = 20%