Question

a train wheel of diameter 49 cm travels a distance of 154 m. How many numbers of revolution does the wheel make?

Answer 1

Radius of wheel = diameter/2 = 49/2 cm
Circumference = 2πr = 2 × 22/7 × 49/2 = 154 cm 
Distance = 154 m = 15400 cm
No. of revolutions = 15400 cm / 154 cm = 100.

Answer 2

d=49cm
r=49/2 cm
distance travelled in one revolution=2πr
=2*(22/7)*(49/2)
=154cm

Total distance travelled=154m=15400cm

So. number of revolutions =15400/154
=100
so it takes 100 revolutions