A wheel completes 2000 rotations in covering a distance of . . .

Question : A wheel completes 2000 rotations in covering a distance of 9.5 km . The diameter of the wheel is

(a) 1.5 m

(b) 1.5 cm

(c) 7.5 m

(d) 7.5 cm

Doubt by Faizan

Solution : 

No. of Rotation = 2000

Distance Covered by Wheel
= 9.5 km
= 9.5×1000 
= 9500 m

No. of Rotation
= (Total Distance Covered)/Distance Covered by Wheel in one radiation)
= Distance/2πr
2πr = Distance/No. of Rotation 
2πr=9500/2000
2πr=95/20
2πr=19/4
2×(22/7)r=19/4
2r=(19×7)/(4×22)

d = 133/88
d = 1.511 m
d = 1.5 m

Diameter of the wheel = 1.5 m

Hence, a) would be the correct option.