Aptitude Day 259

Problems on Time and Distance:

1. While covering a distance of 49 km, a man noticed that after walking for 2 hours 20 minutes, the distance covered by him was 3/4 of the remaining distance. What was his speed in meters per second?

Solution:

                  Let x be the speed.

              

                  Distance covered in 2 hours 20 minutes = x*2(20/60) = x* 2(1/3) = 7x/3 km.

                  Remaining distance = (49- 7x/3) km.

                  7x/3 = 3/4 (49- 7x/3)

                 By solving the above equation, we get

                 x = 9 km/hr = 9*(5/18) = 2(1/2) m/sec.

2. A man travelled from the village to the post-office at the rate of 20 kmph and walked back at the rate of 5 kmph. If the whole journey took 2 hours 30 minutes, find the distance of the post-office from the village.

Solution:

                 Average speed = (2*20*5)/(20+5) = 8.

                 The whole distance travelled = 8*2(1/2) = 8*5/2 = 20 km.

                 Distance between the post-office and the village = 20/2 = 10 km.