NISHA answer is A speed of deepa and the time taken by her gives the actual distance travelled.that can be used to calculate the speed of hema.now we increase their speeds by 10 Kmph and 5 Kmph respectively and obtain the time taken to travel the distance and eventually get the difference in times
Correct Answer: 54 min
Solution:
Average Speed of Deepa = 30 kmph.
Time taken to reach the destination = 6 hours.
So, total distance of destination = 6 *30 = 180 Km.
Time taken to covered 180 km by Hema = 4 hours.
Speed of Hema = 180 /4 = 45 kmph.
Deepa's new average speed = 30 +10 = 40 kmph.
Time Taken = 180/40 = 4.5 hours.
Hema's new average speed = 45 +5 = 50 Kmph.
Time taken by Hema = 180/50 = 3.6 hours.
Time difference = 4.5 - 3.6 = 0.9 hours = 0.9 *60 = 54 minutes.