## Time and Distance  For SBI PO Set – 7

1) If a person walks at 12 kmph he covers a certain distance. If he walks at 17 kmph, he covers 8.5 km more. How much distance did he actually cover?

a) 24 km

b) 4 km

c) 36 km

d) 6 km

b) 4 km

Explanation

The difference between the speeds is 5 kmph.

So for 8.5 miles it takes 8.5/5 = 1.7 hrs

Therefore Actual distance = 12 x 1.7 = 20.4 km

2) A and B are moving in a circular track of 10 km in the same direction. Their speeds are 4 kmph and 5 kmph respectively. When will they meet each other if B starts at 8 am and A starts at 9:30 am from a same point?

a) 12 am

b) 10.30 am

c) 12 pm

d) 2.30

c) 12 pm

Explanation

Relative Speed = 5 – 4 = 1 kmph

Relative distance = 2.5 km (Since B started and travelled 7.5 km in an hour, he is 2.5 km ahead of A)

Time taken = 2.5 hours

They will meet at 9.5 + 2.5 = 12 pm

3) The speed of the stream is 5km/hr.A motorboat goes 10 km upstream and back again to the starting point in 50 minutes.what is the speed of the motorboat in still water?

a) 20km/hr

b) 25km/hr

c) 28km/hr

d) 30km/hr

e) None of these

b) 25km/hr

Explanation

let the speed of the motorboat in still water be x km/hr

The speed of the motorboat along the stream=x+5 km/hr

The speed of the motorboat against the stream=x-5 km/hr

10/x+5 + 10/x-5=50/60

10(x-5+x+5)/(x+5)(x-5)=5/6

20x*6=5(x^2-25)

5(x^2-25)=5(24x)

x^2-25-24x=0

x^2-24x-25=0

now we take factorize

x=25 or -1

x=25 km/hr

4) In a flight of 600kms,an aircraft was slowed down due to bad wheather. its average speed for the trip is reduced by 200kms/hr. and the time of flight increased by 30 min. the duration of the flight is.

a) 1hr

b) 2hrs

c) 3hrs

d) 4hrs

e) 5hrs

a) 1hr

Explanation

let the duration of flight be “t” hours

s=d/t

s1-s2=200kms/hr

600/t – 600/t+1/2=200

600/t – 2*600/2t+1=200

(2t+1)600-t*1200=200t(2t+1)

3(2t+1)-6t=t(2t+1)

6t+3-6t=2t^2+t

t(2t+3)-1(2t+3)=0

(2t+3)(t-1)=0

t=1 hour

5) A business man travelled 120km by bus ,Which formed 2/5 of his trip.He travelled 1/3 of the whole trip by car and the rest by train.The distance travelled by train is

a) 60km

b) 70km

c) 80km

d) 90km

e) None of these

Explanation

2/5 x = 120km

Total distance = x(5×120)/2 = 300km

Remaining trip = 300 – 120 = 180

Distance travelled by car = 300/3 = 100km

Distance travelled by train = 180 – 100 = 80km

6) Two trains are moving in opposite direction having speed in the ratio 5:7. First train crosses a pole in 12 second and second train crosses the same pole n 15 second. Find the time in which they can cross each other completely.

a) 55/4 sec

b) 53/4 sec

c) 57/4 sec

d) 59/4 sec

e) None of these

a) 55/4 sec

Explanation :

Let the length of first train and second train be a and b meter. Then

a = 5x*12 = 60x and b = 7x*15 = 105x

They are moving in opposite direction, 165x = (12x)*T

T = 165/12 = 55/4 sec

7) Two cars start together in the same direction from the same place. The first goes with uniform speed of 10 kmph. The second goes at a speed of 8 kmph in the first hour and increases its speed by 1/2 kmph each succeeding hours. After how many hours will the second car overtake the first, if both cars go non stop?

a) 8 hours

b) 7 hours

c) 6 hours

d) 9 hours

e) 5 hours

d) 9 hours

Explanation :

The second car overtake the first car in x hours

Distance covered by the first car in x hours = Distance covered by the second car in x hours

10x = x/2[2a + (x-1)d] 10x = x/2[2*8 + (x-1)1/2] x = 40 -31 = 9

8) A person covered some distance in 24 hours. He covered half the distance by rail @ 75 km per hour and the rest by car @ 45 km/hr. The total distance covered by him was

a) 900 km

b) 1350 km

c) 675 km

d) 2700 km

e) None of these

b) 1350 km

Explanation

Lets the total distance be 2D. Now

D = 675

Total distance = 2 x D = 2 x 675

= 1350 km

9)  A person covered some distance in 24 hours. He covered half the distance by rail @ 75 km per hour and the rest by car @ 45 km/hr. The total distance covered by him was

a) 900 km

b) 1350 km

c) 675 km

d) 2700 km

e) None of these

b) 1350 km

Explanation

Lets the total distance be 2D. Now

D/75 + D/45 = 24

D = 675

Total distance = 2 x D = 2 x 675

= 1350 km

10) A truck covers a distance of 256 km at the speed of 32 km/h. What is the average speed of a car which travels a distance of 160 km more than the truck in the same time?

a) 46 km/h

b) 52 km/h

c) 49 km/h

d) 64 kmh

e) None of these