Aptitude Day 266

Problems on Time and Distance:

1. A cycle starts with a speed of 7 m/s with its speed increasing every 2 minutes by 1 m/s. In how many minutes will it cover 48 m?

Solution:

                  Distance covered in 1^st 4 minutes = 7*2 + 8*2 = 14+16 = 30 m.

                  Remaining  distance = 48-30 = 18 m.

                  Time taken = 18/9 = 2 seconds.

                  Total time taken = (2+2) minutes +2 seconds 

                                             = 4 minutes 2 seconds.

2. A train covers a distance of 20 km in 15 minutes. If its speed is decreased by 10 km/hr, the time taken by it to cover the same distance will be:

Solution:

                  Speed = 20* 1/18*[60] = 80 km/hr.

                  Decreased speed = 80 – 10 = 70 km/hr.

                  The time taken to cover the same distance = 20/70*[60] 

                                                                                      = 17(1/7) minutes.