A man walks a certain distance with certain speed. If he walks 1/2 km an hour faster, he takes 1 hour less. But, if he walks 1 km an hour slower, her takes 3 more hours. Find the distance covered by the man and his original rate of walking.

Let the original speed, original time taken and distance be ‘a’, ‘t’ and ‘d’.


Speed = distance/time


⇒ d = at ------- (1)


Given, if he walks 1/2 km an hour faster, he takes 1 hour less. But, if he walks 1 km an hour slower, her takes 3 more hours.


⇒ d = (a + 0.5)(t – 1)


⇒ d = at + 0.5t – a – 0.5 -------- (2)


Also, d = (a – 1)(t + 3) ---------- (3)


Solving the three equations we get, d = 36 km and a = 4 km/hr


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