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Q:

A goods train runs at the speed of 72 kmph and crosses a 250 m long platform in 26 seconds. What is the length of the goods train?

A) 230 m B) 240 m
C) 260 m D) 270 m
 
Answer & Explanation Answer: D) 270 m

Explanation:

Speed =[ 72 x (5/18) ]m/sec= 20 m/sec.

Time = 26 sec.

Let the length of the train be x metres.

Then,[ (x+250)/26 ]= 20

=> x + 250 = 520

=> x = 270.

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Filed Under: Problems on Trains

Q:

Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time (in seconds) which they take to cross each other, is:

A) 9 B) 9.6
C) 10 D) 10.8
 
Answer & Explanation Answer: D) 10.8

Explanation:

Relative speed = (60 + 40) km/hr =[ 100 x ( 5 / 18 ) ]m/sec = ( 250 /9 ) m/sec.
Distance covered in crossing each other = (140 + 160) m = 300 m.
Required time = [ 300 x ( 9/250 ) ] sec = ( 54/ 5 )sec = 10.8 sec.

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Q:

A train moves past a telegraph post and a bridge 264 m long in 8 seconds and 20 seconds respectively. What is the speed of the train ?

A) 69.5 km/hr B) 70 km/hr
C) 79 km/hr D) 79.2 km/hr
 
Answer & Explanation Answer: D) 79.2 km/hr

Explanation:

Let the length of the train be x metres and its speed by y m/sec.


Then, x/y = 8 => x = 8y


Now, (x+264)/20 = y
8y + 264 = 20y
y = 22.
Speed = 22 m/sec = (22*18/5) km/hr = 79.2 km/hr.

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Q:

A 270 metres long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. What is the length of the other train ?

A) 230 m B) 240 m
C) 260 m D) 320 m
 
Answer & Explanation Answer: A) 230 m

Explanation:

Relative speed = (120 + 80) km/hr


=(200*5/18)m/s = (500/9)m/s

 

Let the length of the other train be x metres.

 

Then, x+270/9 = 500/9 

 

=>  x + 270 = 500

 

=>  x = 230.

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Q:

0.1 decates ago, Vijaya was quadrice as old as her daughter Simran. 0.6 decades hence, Vijaya’s age will beat her daughter’s age by 0.9 decades. The proportion of the current ages of Vijaya and Simran is : [ 0.1 Decates =1 Year; quadrice = 4 times]

A) 8:1 B) 10:2
C) 11:4 D) 13:4
 
Answer & Explanation Answer: D) 13:4

Explanation:

Let, Ages of Vijaya and Simran – 1 year ago was 4A and A years correspondingly.
Then, [(4A + 1) + 6] – [(A + 1) + 6] = 9
3A = 9  => A = 3

 

Needed Ratio = (4A + 1) : (A + 1) = 13 : 4

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Filed Under: Problems on Ages

Q:

If two times of the daughter’s age in years is included to the mother’s age, the total is 70 and if two times of the mother’s age is included to the daughter’s age, the total is 95. So the Mother’s age is,

A) 30 B) 38
C) 40 D) 41
 
Answer & Explanation Answer: C) 40

Explanation:

Let daughter’s age = A and mother’s age = B
Given: 2A+B = 70 and A+2B = 95
Solving B, we will get B = 40.

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Q:

The ratio of the ages of Maala and Kala is 4 : 3. The total of their ages is 2.8 decades. The proportion of their ages after 0.8 decades will be [1 Decade = 10 years]

A) 4:3 B) 12:11
C) 7:4 D) 6:5
 
Answer & Explanation Answer: D) 6:5

Explanation:

Let, Maala’s age = 4A and Kala’s age = 3A
Then 4A + 3A = 28
A = 4
Maala’s age = 16 years
and Kala’s age = 12 years
Proportion of their ages after 8 is = (16 + 8) : (12 + 8)
= 24 : 20
= 6 : 5

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Q:

A man’s current age is 25 of the age of his father. After 8 years, he will be 12 of the age of his father. What is the age of father at now ?

A) 50 B) 40
C) 33 D) 30
 
Answer & Explanation Answer: B) 40

Explanation:

Let, father’s current age is A years.
Then, Man’s current age = 25*Ayears.

 25*A+8=12A+8

2(2A+40) = 5(A+8)

A = 40

 



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Filed Under: Problems on Ages