Wipro WILP Time, speed and Distance Quiz- 1

Speed of yatch downstream

= Distance covered Time taken=45/2 = 12.9 km/h

Now, speed of boat upstream

= Distance coveredTime taken=45/7.1 = 6.4 km/h

Now, speed of boat

= Speed downstream+Speed upstream2

= 12.9 + 6.4 = 19.3 km/h

Let the speed of goods train be x km/hr.
Then, (67+x)×(5/18)=293.5/11

⇒ x= 29.05 km/hr

Let the speed of the stream be x km/hr. Then,

Speed downstream = (21 + x) km/hr,

Speed upstream = (21 - x) km/hr.

45/(21+ x) + 45/ (21 - x) =4(1/2)

2025/(441 - x²) = 9/2

9x² = 181

x = 4.48 km/hr.

Let the speed of the cyclist be x km/h and wind be y km/h
1/(x+y)=3/60
X+y=20..........i

And
1/(x-y)=4/60
x-y==15.........ii
On solving both the equations we get:
x=35/2
,y=5/2
Now, time taken by cyclist without wind: (2/35)*60=24/7 min

Let the car travel a distance of 2d km, total.

The first half of the distance takes d km/30 kmph = d/30 hr.

The second half of the distance takes d km/50 kmph = d/50 hr.

So the total time taken to cover 2d km = (d/30)+(d/50) = 80d/150 hr.

The average speed of the car = Total distance/ total time = 2d/[80d/150]

= 2d*150/80d

= 37.5 kmph.

Let the speed of the current be x km/hr
Thus upward speed =(6+x) km/hr
and downward speed =(6−x) km/hr

Let distance traveled be y, then
y/(6−x) = 3y/(6+x)

⇒ x= 6 km/hr

Given speed = 71 km/hr = 71×18/5= 255.6 m/s

Let the length of the bridge = x mts

Given time taken to cover the distance of (183 + x)mts is 30 sec.

We know speed = distancetimem/s

⇒255.6=183+30x
--> x = 242 mts.

(x+142)/38 = x/23

=> 23(x + 142) = 38x

=> 23x + 3266 = 38x

=> 3266 = 15x

=> x = 217.73 m.

Let the distance of train be any value ( if you don't want to solve by taking x. )

Let length of each train = L.C.M. of the the time given 29 and 19 (for simplicity) = 551 meter.

Passing a pole means, crossing its own length.

So, for train 1.

Distance covered in passing a pole = length of train 1 =551 meter.

Time taken = 29 sec.

So, Speed of train 1 = 551/29 = 19 m/s

For train 2:

Speed of train 2 = 551/19 = 29 m/s

( These data can be assumed in solving relatively. If x would have been taken in place of 551, the process would have been the same. If confused, think x=551. )

Opposite direction movement, time taken to cross:

In opoosite direction, the relative speed is added up.

So, relative speed = 19 + 29 = 48 m/s

Relative Distance covered for both trains to cross each other = sum of length of both trains

= 551 + 551 = 1102 m

So, time taken for both trains to cross each other= distance/ relative speed

= 1102/ 48 sec

=22.9 sec.

Since the train and man are moving in opposite directions,

The relative speed = 75-(-8.8) kph = 75 + 8.8 = 83.8 kph

83.8 km/h in m/s = 83.8*5/18 = 23.27m/s

Total distance to be covered = 135 m (length of the train)

So, time = distance/speed = 135 divided by 23.27 which equals 5.80 s.

So, the required time is 5.80 seconds.