731. A train can travel 50% faster than a car. Both start from point A at the same time and reach point B 75 kms away from A at the same time. On the way, however, the train lost about 12.5 minutes while stopping at the stations. What is the speed of the car?
A. 80 kmph
B. 102 kmph
C. 120 kmph
D. 140 kmph
732. A and B walk around a circular track. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. If they start at 8 a.m. from the same point in opposite directions, how many times shall they cross each other before 9.30 a.m.?
Relative speed = Speed of A + Speed of B (∴ they walk in opposite directions)
= 2 + 3 = 5 rounds per hour
=> They cross each other 5 times in 1 hour and 2 times in 1/2 hour
Time duration from 8 am to 9.30 am = 1.5 hour
Hence they cross each other 7 times before 9.30 am
733. If a man walks at 6 kmph, he can reach his destination at 9:00 am. However, he walks a little slower and reaches only at 10:00 am. If the distance to his destination was 12 km, at what speed did he walk?
A. 5 kmph
B. 4 kmph
C. 4.5 kmph
D. 3 kmph
If he travels at 6 kmph,
time taken to reach = 12/6 = 2 hours But he takes 3 hours.
Speed = 12/3 = 4 kmph
734. In a race, a car travelled at a speed of 150 kmph. If it had travelled at 180 kmph, it would have completed the race before 3 minutes. Find the length of the track.
A. 50 km
B. 45 km
C. 40 km
D. 30 km
735. Asghar traveled from his house to his office at 10 km/hr and returned at rate of 9 km/hr. Rohit travelled through the same path both ways at 12 km/hr and took 10 minutes less than Asghar. What is the distance between Asghar’s house and his office?
Average speed for Raj is: v = (2*9*10)/(9+10) = 180/19 km/hr = 50/19 m/s
Average speed for Rohit = 12 km/hr = 10/3 m/s
Now, v = d/t
As d is same, v*t = constant.
Let, t be the time taken by Rohit in seconds. Hence, time taken by Raj is (t +600)s
50/19 * (t + 600) = 10/3 * t
150*(t + 600) = 190t
t = 2250s
Let d be the distance between the house and the office
2d = 2250 * 10/3
2d = 7500 m
d = 3750m
736. An aeroplane covers a certain distance at a speed of 240 kmph in 5 hours. To cover the same distance in 5/3 hours, it must travel at a speed of:_________?
A. 660 km/hr
B. 680 km/hr
C. 700 km/hr
D. 720 km/hr
Distance = Speed x Time = 240 x 5 km
New time =5/3 hr
Hence, new speed = Distance/Time =240*5/5/3
737. A man covered a certain distance at some speed. If he had moved 3 kmph faster, he would have taken 40 minutes less. If he had moved 2 kmph slower, he would have taken 40 minutes more. What is the the distance in km?
738. A car gives a mileage of 20 km per liter of petrol when driven at a constant speed of 50 kmph but the mileage decreases by 10% when driven at a speed of 70 kmph. How many km can the car travel with 12 liters of petrol if it travels a speed of 70 kmph?
A. 216 km
B. 240 km
C. 228 km
D. 200 km
739. A car travels 50% faster than a bike. Both start at the same time from A to B. The car reaches 25 minutes earlier than the bike. If the distance from A to B is 100 km, find the speed of the bike.
A. 120 km
B. 100 km
C. 80 km
D. 75 km
Let the speed of the bike be x kmph. Then the speed of the car will be 3x/2 kmph. Time taken by the bike
t1 = 100/x Time taken by the bike
t2 = 100/(3x/2) t1 – t2 = 25/60 (100/x) – (100/(3x/2)) = 5/12 Solving the equation, x = 80 kmph
740. Two trains 120 miles apart travel towards each other. The 1st train travels at 70 mph while the 2nd at 50 mph. A bird starts flying from the location of the faster train towards the other train at 85 mph and when it reaches the slower train it turns back and flies in the other direction at the same speed. When it reaches the faster train it again turns around and repeats the same procedure again and again. When the train collide, how far will the bird have flown?
A. 85 miles
B. 70 miles
C. 50 miles
D. 120 miles