Mohan takes 2 hours more than Kishore to walk 63 km. If Mohan increases his speed by 50%, then he can make it in 1 hour less than Kishore. How much time does Kishore take to walk 63 km?
Answer & explanation
Correct answer: option 1
Speed is increased by 50%
50% = \(\frac{1}{2}\)
Ratio of , Old speed : New speed
2 : 3
Old speed = 2s km/h
New speed = 3s km/h
Actual time = t hours
Initial time = ( t + 2 ) hours
Final time = ( t - 1 ) hours
We know that,
Distance = Speed x Time
63 = \(\frac{S1 × S2 }{S2 - S1}\) × ( t1 - t2 )
63 = \(\frac{3s × 2s }{3s - 2s}\) × ( t + 2 - t + 1 )
63 = 6s × 3
s = 3.5
Now, Initial speed of Mohan = 2s = 2 x 3.5 = 7 km/h
Time taken by Mohan = \(\frac{63}{7}\) = 9 hours
Time taken by kishore = 9 - 2 = 7 hours