Discussion
Home ‣ Aptitude ‣ Time and Distance Comments
- Question
- A car is moving with the speed of 47.52km/hr and the radius of the wheel of car is 21 cm. Calculate the approximate number of revolutions made by the wheel in one minute.
Options- A. 250 rpm
- B. 200 rpm
- C. 600 rpm
- D. 300 rpm
- Correct Answer
- 600 rpm
ExplanationSpeed in cm/minute = (Speed in km/hr x 1000 x100 )/60
= 47.52x(50/3)
=79200 cm/min
And Circumference of circle = 2?r
=2 x ( 22 / 7 ) x 21
=132
No. of revolutions = ( Speed in cm/minute ) / circumference of circle in cm
=79200 / 132
=600 rpm - 1. If a train runs at 5/6 of its original speed, then it reaches the station 10 min late. Then find out the usual time taken by train to cover the distance.
Options- A. 40 min
- B. 45 min
- C. 50 min
- D. 55 min Discuss
- 2. The average speed of a car is 75 km/h. The driver first decrease its average speed by 40% and then increase it by 50%. What is the new average speed now?
Options- A. 67.5 km
- B. 60 km
- C. 90 km
- D. 60.5 km Discuss
- 3. A train covers a distance in 1 h 40 min, if it runs at a speed of 96 km/h on an average. Find the speed at which the train must run reduce the time of journey to 1 h 20 min.
Options- A. 120 km/h
- B. 90 km/h
- C. 144 km/h
- D. 150 km/h Discuss
- 4. A person goes from one point to another point with a speed of 5 km/h and comes back to starting point with a speed of 3 km/h. Find the average speed for the whole journey.?
Options- A. 4.5 km/h
- B. 4 km/h
- C. 4. 25 km/h
- D. 3. 75 km/h Discuss
- 5. John started from A to B and Vinod from B to A. If the distance betweeen A and B is 125 km and they meet at 75 km from A, what is the ratio of John's speed to that of Vinod's speed?
Options- A. 2 : 3
- B. 3 : 2
- C. 4 : 3
- D. 5 : 4 Discuss
- 6. A man walking at 3km/hr crosses a square field diagonally in 2 min. The area of the field is?
Options- A. 25 acres
- B. 30 acres
- C. 50 acres
- D. 60 acres Discuss
- 7. A certain distance is covered at a certain speed. If half of this distance is covered in double the time, the ratio of the two speed is?
Options- A. 4:1
- B. 1.4
- C. 2:1
- D. 1:2 Discuss
- 8. A is twice as fast as B and B is thrice as fact as C is . The journey covered by C in 42 minute, will be covered by A in?
Options- A. 14 min
- B. 28 min
- C. 63 min
- D. 7 min Discuss
- 9. Ram travels a certain distance at 3 km/hr and reaches 15 min late. If he travels at 4 km/hr he reaches 15 min earlier. The distance he has to travel is?
Options- A. 4.5 km.
- B. 6 km.
- C. 7.2 km.
- D. 12 km. Discuss
- 10. A thief steals a car at 1:30 p.m. and drives it at 45 km an hour. The theft is discovered at 2 p.m. and the owner sets off in another car at 50 km an hour. He will overtake the thief at?
Options- A. 3:30 p.m.
- B. 4 p.m.
- C. 4:30 p.m.
- D. 6 p.m. Discuss
Time and Distance problems
Search Results
Correct Answer: 50 min
Explanation:
Let the actual speed of train be x and actual time taken be y
Then new speed of train = 5x/6
Therefore, new time taken = 6y/5 (as distance is same in both case)
Given, 6y/5 - y = 1/6 hr , therefore actual time = 50 min
Correct Answer: 67.5 km
Explanation:
Required average speed = 75 x {(100 - 40)/100} x {(100 + 50)/100}
= 75 x 3/5 x 3/2
= 67.5 km/h
Correct Answer: 120 km/h
Explanation:
Distance= Speed x Time = 96 x (100/60) = 160 km
New time = 80/60 h = 4/3 h
New speed = 160 x 3/4 = 40 x 3 =120 km/h
Correct Answer: 3. 75 km/h
Explanation:
Average speed = 2AB/(A + B)
= 2 x 5 x 3/(5 + 3)
= 30/8
= 3.75 km/h
Correct Answer: 3 : 2
Explanation:
John's speed : Vinod's speed = 75 : ( 125 - 75 )
= 75 : 50 = 3 : 2
Correct Answer: 50 acres
Explanation:
speed = 3 x ( 5/18 ) m/sec.
= 5 / 6 m/sec.
? Distance covered in 2 min. = ( 5 / 6) x 2 x 60 m
= 100 m.
? Length of diagonal = 100 m
Area of the field = 1/2 x diagonal2
=1/2 x 100 x 100 m2
= 5000 m2
= 50 acres.
Correct Answer: 4:1
Explanation:
Let x km . be covered in y hrs.
then, 1st speed = (x / y) km/hr.
2nd speed = [(x/2) / 2y)] km/hr.
= (x/4y) km/hr.
? Ratio of speed = x/y : x/4y = 1 :1/4 = 4: 1
Correct Answer: 7 min
Explanation:
Let C' s speed = x km/hr.
Then, B's speed = 3x km/hr.
and A's speed = 6x km/hr.
? Ratio of speed of A, B, C
= 6x : 3x : x = 6 : 3 : 1
Ratio of times taken = 1/6 : 1/3 : 1 or 1 : 2 : 6
? 6 : 1 : : 42 : t
? 6t = 42
? t = 7 min.
Correct Answer: 6 km.
Explanation:
Let the distance be x km.
Then, x/3 - x/4 = 30/60
? (4x - 3x ) / 12 = 1/2
? x = 6 km.
Correct Answer: 4 p.m.
Explanation:
Distance covered by thief in (1/2 ) hour = 20 km.
Now , 20 km is compensated by the owner at a relative speed of 10 km/hr in 2 hours so, he overtake the thief at 4 p.m.
Comments
There are no comments.More in Aptitude:
Programming
Copyright ©CuriousTab. All rights reserved.