What is the radius (in cm) of the tyre in a car, if it covers 0.396 km in 300 rotations? (Use π = 227)
21 cm
The circumference of the tyre = 2πr (Distance travelled in each rotation)
Total Distance = Distance covered in 1 rotation x Number of rotations
⇒0.396=2×227×r×300
⇒r=0.396×72×22×300
Hence r = 0.00021 km or 21 cm.