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Q:

A train overtakes two girls who are walking in the  opposite direction in which the train  is going at the rate of 3 km/h and 6km/h and passes them completely in 36 seconds and 30 seconds respectively. The length of the train is:

A) 120m B) 150m
C) 125m D) None of these

Answer:   B) 150m

Explanation:

Let the length of the train e x meter, and let the speed of train be y km/h, then

                     \inline x=\left ( y+3 \right )\frac{5}{18}\times 36 ........(1)

       and        \inline x=\left ( y+6\right )\frac{5}{18}\times 30 ........(2)

From eq (1) and (2), we get

                   \inline (y+3)\times 36 = ( y+6)\times 30

                     y = 12 km/h

\inline \therefore                 \inline x=(y+3)\times \frac{5}{18}\times 36

                     x= 150 m

Q:

A Bus is running at 9/10 of its own speed reached a place in 22 hours. How much time could be saved if the bus would run at its own speed ?

A) 1.5 hrs B) 1.7 hrs
C) 2.2 hrs D) 3.5 hrs
 
Answer & Explanation Answer: C) 2.2 hrs

Explanation:

Let the original Speed be "s" kmph
And the usual time be "t" hrs
Given that if the bus is running at 9s/10 kmph the time is 22 hrs
=> [9s/10] x 22 = t x s
=> 99/5 = t
=> t = 19.8 hrs

 

Hence, if bus runs at its own speed, the time saved = 22 - 19.8 = 2.2 hrs.

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1 4
Q:

How many seconds will a 800 meter long train moving with a speed of 63 km/hr take to cross a man walking with a speed of 3 km/hr in the direction of the train ?

A) 48 B) 52
C) 38 D) 42
 
Answer & Explanation Answer: A) 48

Explanation:

Here distance d = 800 mts
speed s = 63 - 3 = 60 kmph = 60 x 5/18 m/s
time t = = 48 sec.

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1 2
Q:

P is faster than Q. P and Q each walk 24 km. The sum of their speeds is 7 km/hr and the sum of times taken by them is 14 hours. Then, P's speed is equal to ?

A) 3 km/hr B) 4 km/hr
C) 5 km/hr D) 6 km/hr
 
Answer & Explanation Answer: B) 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

- 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.

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1 10
Q:

A man walks at a speed of 2 km/hr and runs at a speed of 6 km/hr. How much time will the man require to cover a distance of 20 1/2 km, if he completes half of the distance, i.e., (10 1/4) km on foot and the other half by running ?

A) 12.4 hrs B) 11.9 hrs
C) 10.7 hrs D) 9.9 hrs
 
Answer & Explanation Answer: B) 11.9 hrs

Explanation:

We know that

Time = Distance/speed
Required time = (10 1/4)/2 + (10 1/4)/6
= 41/8 + 41/6
= 287/24 = 11.9 hours.

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1 7
Q:

An express traveled at an average speed of 100 km/hr, stopping for 4 min after every 75 km. How long did it take to reach its destination 600 km from the starting point ?

A) 6 hrs 24 min B) 6 hrs
C) 7 hrs 21 min D) 6 hrs 28 min
 
Answer & Explanation Answer: D) 6 hrs 28 min

Explanation:

Time taken to cover 600 km = 600/100 = 6 hrs.

Number of stoppages = 600/75 - 1 = 7

Total time of stoppages = 4 x 7 = 28 min

Hence, total time taken = 6 hrs 28 min.

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