Question
Quantitative Aptitude Question on Time Speed and Distance
The wheels of bicycles A and B have radii 30 cm and 40 cm, respectively. While traveling a certain distance, each wheel of A required 5000 more revolutions than each wheel of B. If bicycle B traveled this distance in 45 minutes, then its speed, in km per hour, was
A
18π
B
12π
C
16π
D
14π
Answer
12π
Explanation
Solution
Distance for bicycle A in one revolution = 60π cm and for bicycle B = 80π cm.
Let B make 'n' revolutions to cover the distance, then A would make (n + 5000) revolutions to cover the same distance.
Equation: n × 80π = (n + 5000) × 60π Solving for n gives n = 15000.
Distance traveled by B = n × 80π cm = 12 km.
Time taken by B = 45 min = 3/4 hrs.
Therefore, the speed of B = 16π km/h.