Time and Distance and Time and work (UPSC) Part-I

Total Questions: 33

31. Four cars are hired at the rate of ₹ 6 per km plus the cost of diesel at ₹ 40 a litre. In this context, consider the details given in the following table: [2013-II]

CarMileage (km/l)HoursTotal Payment (₹)
A8202120
B10251950
C9242064
D11221812

 

Which car maintained the maximum average speed?

Correct Answer: (a) Car A
Solution:

32. A thief running at 8 km/hr is chased by a policeman whose speed is 10 km/hr. If the thief is 100 m ahead of the policeman, then the time required for the policeman to catch the thief will be [2013-II]

Correct Answer: (b) 3 min
Solution:If we consider the difference of speeds, policeman is 2 km/ hr leading speed and he can catch the thief at 100 m

ahead by (100m/2 kmph) = 100/1000 × 2 × 60 = 3 min.

33. A train travels at a certain average speed for a distance of 63 km and then travels a distance of 72 km at an average speed of 6 km/hr more than its original speed. If it takes 3 hours to complete the total journey, what is the original speed of the train in km/hr? [2013-II]

Correct Answer: (c) 42
Solution:Let the original speed = x
Total time taken = 3 hr