10
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

x=y+3×518×36   --------(1)   and   

x=y+6×518×30  ---------(2)

  

From eq (1) and (2), we get      

y = 12 km/h

Therefore,  x=(y+3)×518×36   =>  x= 150 m

Q:

A man covers half of his journey by train at 60 km/hr, half of the remaining by bus at 30 km/hr and the rest by cycle at 10 km/hr. Find his average speed during the entire journey?

A) 32 kmph B) 20 kmph
C) 18 kmph D) 24 kmph
 
Answer & Explanation Answer: D) 24 kmph

Explanation:

Let the total distance of the journey of a man = d kms

Now, the average speed of the entire journey = dd120 + d120 + d40  = 24 kmph.

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5 115
Q:

The respective ratio between the speed of a bike, a van  and lorry is 3 : 5 : 2. The speed of the van is 250 percent of the speed of the lorry which covers 360 km in 12 hours. What is the average speed of the bike and the van together?

A) 60 kmph B) 62 kmph
C) 64 kmph D) 63 kmph
 
Answer & Explanation Answer: A) 60 kmph

Explanation:

Speed of lorry = 36012 = 30 kmph

Speed of van =250100 x 30 = 75 kmph

Speed of bike = 35 x 75 = 45 kmph

Therefore, now required average speed of bike and van  = 75 + 452= 60 kmph.

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4 130
Q:

If a girl cycles at 10 kmph, then she arrives at a certain place at 1 p.m. If she cycles at 15 kmph, she will arrive at the same place at 11 a.m. At what speed must she cycle to get there at noon?

A) 14 kmph B) 13 kmph
C) 12 kmph D) 11 kmph
 
Answer & Explanation Answer: C) 12 kmph

Explanation:

The distance is constant in this case.

Let the time taken for travel with a speed of 10 kmph be 't'.

Now the speed of 15 kmph is 3/2 times the speed of 10 kmph.

Therefore, time taken with the speed of 15 kmph will be 2t/3 (speed is inversely proportional to time)

Extra time taken = t - 2t/3 = t/3

=> 1pm - 11am = 2hrs

=> t/3 = 2h

=> t = 6 hrs.

Now, Distance = speed x time = 10 x 6 = 60 kms

Time he takes to reach at noon = 6 - 1 = 5 hrs

Now, Speed = 60/5 = 12 kmph.

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10 489
Q:

In a daily morning walk three persons step off together. their steps measure 75 cm, 80 cm and 85 cm respectively. What is the minimum distance each should walk so that thay can cover the distance in complete steps  ?

A) 222 m 44 cm B) 204 m
C) 201 m 21 cm D) 208 m
 
Answer & Explanation Answer: B) 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.

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7 388
Q:

Three friends Rudra, Siva and Anvesh start to run around a circular stadium. They complete a revolution in 24, 36 and 30 seconds respectively. After how many minutes will they meet at the starting point ?

A) 60 B) 120
C) 360 D) 6
 
Answer & Explanation Answer: D) 6

Explanation:

For this we have to find the LCM of 24, 36 and 30

LCM of 24, 36 and 30 = 360 sec

360/60 min = 6 minutes.

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10 567
Q:

Kamal consistently runs 240 meters a day and on Saturday he runs for 400 meters. How many kilometers will he have to run in four weeks ?

A) 5.75 kms B) 7.36 kms
C) 8.2 kms D) 6.98 kms
 
Answer & Explanation Answer: B) 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

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4 669
Q:

K and L starts walking towards each other at 4 pm at speed of 3 km/hr and 4 km/hr respectively. They were initially 17.5 km apart. At what time do they meet ?

A) 6:00 am B) 6:30 pm
C) 5:45 am D) 5:52 pm
 
Answer & Explanation Answer: B) 6:30 pm

Explanation:

Suppose they meet after 'h' hours

Then

3h + 4h = 17.5

7h = 17.5

h = 2.5 hours

So they meet at => 4 + 2.5 = 6:30 pm

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9 802
Q:

P, Q and R start simultaneously from A to B. P reaches B, turns back and meet Q at a distance of 11 km from B. Q reached B, turns back and meet R at a distance of 9 km from B. If the ratio of the speeds of P and R is 3:2, what is the distance between A and B ?

A) 99 B) 100
C) 89 D) 1
 
Answer & Explanation Answer: A) 99

Explanation:

Let, Distance between A and B = d

 

Distance travelled by P while it meets Q = d + 11

 

Distance travelled by Q while it meets P = d – 11

 

Distance travelled by Q while it meets R = d + 9

 

Distance travelled by R while it meets Q = d – 9

 

Here the ratio of speeds of P & Q => SP : SQ = d + 11 : d – 11

 

The ratio of speeds of Q & R => SQ : SR = d + 9 : d – 9

 

But given Ratio of speeds of P & R => P : R = 3 : 2

 SPSR = SPSQxSQSR = d+11d+9d-11d-9

 

=> d+11d+9d-11d-9 = 3/2

 

=>  d = 1, 99

 

=> d = 99 satisfies.

 

Therefore, Distance between A and B = 99

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7 567