Two trains 85 m and 75 m long are running in same direction with speeds of 62 km/hr and 44 km/hr respectively. In what time will the first train cross the second train ?

Correct Answer: 60 kmph

Explanation:

Speed of lorry = 360 12 = 30 kmph

Speed of van = 250 100 x 30 = 75 kmph

Speed of bike = 3 5 x 75 = 45 kmph

Therefore, now required average speed of bike and van  = 75 + 45 2= 60 kmph.

Correct Answer: 8 hrs

Explanation:

Given speed of the bike after servicing = 55 kmph

Time taken for travelling some distance at 55 kmph = 5 hrs

Then, 

Distance = Speed x Time = 55 x 5 = 275 kms.

Now, 

Speed of the bike before servicing = 35 kmph

Distance = 275 kms

Now, Time = Distance/Speed = 275/35 = 7.85 hrs =~ 8 hrs.

Correct Answer: Option B

Explanation:

Man walked 6 km at 1.5 kmph, again he walked 8 km at speed of 2 kmph and 40 km at a speed of 8kmph
time taken indivisually:
=> 6/1.5 = 4 m
=> 8/2 = 4 m
=> 40/8 = 5 m

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Average speed of man= total distance/ total time
=> 54/13 =  4 2 13 kmph

Correct Answer: 204 m

Explanation:

To find the minimum distance, we have to get the LCM of 75, 80, 85

Now, LCM of 75, 80, 85 = 5 x 15 x 16 x 17 = 20400

Hence, the minimum distance each should walk so that thay can cover the distance in complete steps = 20400 cms = 20400/100 = 204 mts.

Correct Answer: 75 km/h , 100 km/h

Explanation:

Let Pele x km in 1 hour. so Maradona takes (2h-40min)=1 h 20 min to cover x km. Let speed of Maradona and Pele be M and P respectively than 

                            x =M x (4/3)  and x= P x 1

  => M/P = 3/4 

 Again       300 M = 300 P = 1

? 300 3 k - 300 4 k = 1 

 => k= 25

  M= 3k = 75 km/h   and   P= 4k = 100 km/h 

( Through options it is very easy to solve)

Correct Answer: 500 mts

Explanation:

Using pythagarous theorem,
distance travelled by first train = 36x5/18x30 = 300m
distance travelled by second train = 48x5/18x30 = 400m
so distance between them =?( 90000 + 160000) = ?250000 = 500mts.

Correct Answer: 4 km/hr

Explanation:

Let P's speed = x km/hr. Then, Q's speed = (7 - x) km/ hr.

 

So, 24/x + 24/(7 - x) = 14

 

x 2 - 98x + 168 = 0

 

(x - 3)(x - 4) = 0 => x = 3 or 4.

 

Since, P is faster than Q,

 

so P's speed = 4 km/hr and Q's speed = 3 km/hr.

Correct Answer: 41.25 days

Explanation:

Given Karthik can cover the distance of 200 kms resting 2 hrs per day in 22 days.

 

Let the initial speed be '1'

 

Hence, Time = 22(24hrs - 2)

 

Noe new speed = 2/3

 

Let the number of days he take be 'D'

 

Therefore,  22 24 - 2 x 3 200 = D 24 - 2 x 2 250

 

D = 11 x 3 x 5/4 = 41.25 days. = 41 1/4 days.

Correct Answer: 24 kmph

Explanation:

Let the speed of the train be 'S' kmph

From the given data,

Distance = Length of train = D = 200 mts = 200 x 18/5 kms

Time = 10 sec

given speed of the motorcycler = 12 kmph

Relative speed as they are moving in the same direction = (S - 12) kmph

$$\begin{gathered} ( S - 12) = 200 x 18 5 15 \\ S - 12 = 48 \\ S = 60 kmph \\ \end{gathered}$$

Hence, the speed of the train = S = 60 kmph

Now,

Let the speed of the jeep be 'x' kmph

$$\begin{gathered} 60 - x = 200 x 18 5 20 \\ 60 - x = 36 \\ x = 60 - 36 \\ x = 24 kmph \end{gathered}$$

 

Therefore, the speed of the jeep = x = 24 kmph.

Correct Answer: 7.36 kms

Explanation:

Total running distance in four weeks = (24 x 240) + (4 x 400)

= 5760 + 1600

= 7360 meters

= 7360/1000

=> 7.36 kms