‘x’ meters long train cross a 360 meters long bridge in 20 sec running at the speed of 108 km/hr. If train cross a man running in opposite direction in 6 sec, then what is the speed of man (in km/hr) ?
54 km/hr
58 km/hr
36 km/hr
45 km/hr
72 km/hr
Option C speed of train = 108 * 5/18 = 30m/sec x + 360/30 = 20 x = 240 Let the speed of man = y m/sec 240/30 + y = 6 180 + 6y = 240 y = 10 speed of man = 10 * 18/5 = 36 km/hr
A start driving from Delhi to Bangalore with speed of 20 km/hr and B start driving from Bangalore to Delhi with speed of 28km/hr. If they start at 9 am and distance between Delhi to Bangalore is 240 km, then in how much time they meet each other ?
4 pm
4 : 20 pm
12 : 40 pm
3 pm
2 pm
Option E Total Distance = 240 km relative speed of A and B = 20 + 28 = 48 km/hr Time = 240/48 = 5 hour. They start at 9 am they will meet each other at 2 pm.
A man walking at two-fifth of his usual speed, reaches his destination 6 hour late. What is usual time to reach his destination ?
5 hours
2 hours
4 hours
6 hours
8 hours
Option C let original speed of man = 5x now his speed = 2x ratio of his speed = 5x : 2x his time ratio to reach destination = 2y : 5y 5x – 2x = 6 hours x = 2 hours His usual time = 2 * 2 = 4 hours.
Two man travel by their bikes from Gujrat to Kolkata at a speed of 40 km/hr and 48 km/hr respectively. If one of them takes 5 hours lesser time than the other to reach Kolkata then what is the distance between city Gujrat and Kolkata.
1200 km
2300 km
4200 km
1440 km
2000 km
Option A Let Distance between Gujrat to Kolkata = D km D/40 – D/48 = 5 48D – 40 D/40 * 48 = 5 8D/40 * 48 = 5 D = 1200
The ratio speed of Car and Bike is 4 : 3. Total Distance between point A and point B is 120 km. If Car and Bike start travelling from point A and bike takes 2 hours more time than car, then what is the speed of Car ?
28 km/hr
24 km/hr
20 km/hr
24 km/hr
32 km/hr
Option C Let of Car and Bike = 4x and 3x Distance = 120 km 120/3x – 120/4x = 2 x = 5 speed of Car = 4x = 4 * 5 = 20 km/hr
Rahul goes to his school at rate of 24 km/hr and reaches 8 minutes late. In the next day he goes with 20 km/hr and reached 14 minutes late then, what is distance between his home to school ?
10 km
18 km
14 km
16 km
12 km
Option E Let Actual time to each school = x mixture In 1at case, speed = 24 km/hr Time = (x + 8) minutes Distance = 24(x + 8/60) In 2nd case, speed = 20 km/hr Time = (x + 14) minute Distance = 20 (x+14/60) 24x + 192 = 20x + 280 4x = 88 x = 22 minutes Distance = 24 (22+8/60) = 12 km
Sriman covered one third of his journey at a speed of 20 km/hr, one-fourth of the remaining at the speed of 25 km/hr and the remaining journey at a speed of 15 km/hr. what is his Average speed ?
20km/hr
300/17 km/hr
200/17 km/hr
15km/hr
25km/hr
Option B LCM of 20, 25, and 15 = 300 total distance = 300km 1/3rd of 300 at a speed of 20km/hr Time = 100/20 = 5 hours 1/4th of remaining at a speed of 25 km/hr time = 1/4(300 – 100)/25 = 2 hours remaining 150km at a speed of 15 km/hr time = 150/15 = 10 hour Average speed = 300/5 + 2 + 10 = 300/17 km/hr
If A train crosses 450 meters long platform in 30sec and crosses a pole in 7.5 seconds, then find the length of train ?
200 meters
150 meters
220 meters
320 meters
340 meters
Option B Let length of train = x meters x + 450/30 = x/7.5 x = 150 meters
A and B run 6km/hr and 12 km/hr on a circular track 12 km long, when will they met each other for the first time, if they are running in opposite direction ?
42 minutes
32 minutes
1 hour
2 hour
40 minutes
Option E Total Distance = 12 km/hr relative speed = 12 + 6 = 18 km/hr time = 12/18 = 2/3 = 2/3*60 = 40 minutes.
A thief steal a bike at 8 pm and drive at a speed of 40 km/hr. Police came to know about theft at 11 pm and start chasing him with the speed of 55 km/hr. After how much kilometers police will catch the thief ?
440 km
320 km
450 km
520 km
620 km
Option A speed of thief = 40 km/hr he travelled 8 pm to 11pm = 3 hours distance covered by thief in 3 ours = 3 * 40 = 120 km speed of police = 55 km/hr relative speed = 55 – 40 = 15 km/hr time taken by police to catch the thief = 120/15 = 8 hours distance = 55 * 8 = 440 km
