1 . 
A person completes ajourney in 15 hours, the first half at 12 kmh"1 and the second half at 18 kmh"1. What is the total distance ?


Answer & Explanation
Answer : Option
B


Explanation : 

Let the total distance be x  x/2 km
travelled at a speed 12 kmph1 and another x/2 km
at a speed 18 kmh1
Therefore, Time taken = x/2 x 12 + x/2 x 18 = 15
x/24 + x/36 = 15
Therefore, 5x/72 = 15
Therefore, x = 216 km.






2 . 
An 80metre long train crosses a platform 16 metres long in 12 seconds. What time will it take to cross a bridge of 40m ?


Answer & Explanation
Answer : Option
A


Explanation : 

Speed of train = 80 + 16/12 = 8 ms1
Therefore, Time = 80 + 40/8 = 15 sec






3 . 
A man takes 4 times as long to row up as to row down the river. If the rate of river is 6 kmh1 , what is the rate of man in still water ?


Answer & Explanation
Answer : Option
B


Explanation : 

Let the rate of man be x kmh1
Then (x + 6) = 4(x  6)
or, x + 6 = 4x  24
or, 3x = 30
Therefore, x = 10






4 . 
If the width of a carpet is 5m, how many metres of the carpet will be required to cover a floor of length 40 metres and width 30 metres ?


Answer & Explanation
Answer : Option
D


Explanation : 

Reqd length = 40 x 30/5 = 240 metre






5 . 
'A' is twrice as fast as 'B' , and is therefore able to finish a work in 24 days less than 'B' . What is the time in which they can do it working together ?


Answer & Explanation
Answer : Option
B


Explanation : 

As given, If A does a work in 1 day B does it in 2 days.
Therefore, A does it in 24 days and B does it in 48 days.
Therefore, Together they will take 24 x 48/72 = 16 days.






6 . 
A man rode out a certain distance by car at the speed of 45 kmh 1 and walked back at the rate of 5 kmh1 . The whole journey took 10 hours. What distance did he ride ?


Answer & Explanation
Answer : Option
D


Explanation : 

Let the distance be x km
Therefore, x/45 + x/5 = 10
x + 9x/45 = 10
Therefore, x = 45 km.






7 . 
The speeds of two trains are in the ratio 2 : 3 . They are going in opposite directions along a parallel line. The first train takes 10 seconds and the second train takes 5 seconds to cross a pole. What is the time they will take to cross each other completely ?


Answer & Explanation
Answer : Option
C


Explanation : 

Let their lengths l1 and l2 metres and speed be 2x and 3x ms1
Therefore, l1/2x = 10
Therefore, l1 = 20x
l1/3x = 5
Therefore, l2 = 15x
Relative speed = 2x + 3x = 5x ms1
Therefore, Time = 35x/5x = 7 sec






8 . 
A man can row 5 kmh1 in still water. If the stream is flowing at the speed of 3 kmh1, it takes him 15 hrs to row to a place and come back. What is the distance between the two places ?


Answer & Explanation
Answer : Option
D


Explanation : 

Let the distance be x km.
So upward speed = 5  3 = 2kmh1
and downward speed = 5 + 3 = 8 kmh1
Therefore, x/2 + x/8 = 15
4x + x/8 = 15
Therefore, 5x/8 = 15
Therefore, x = 24 km.






9 . 
If the difference between the squares of two consecutive numbers is 47, what is the smaller number ?


Answer & Explanation
Answer : Option
D


Explanation : 

Let the numbers be (x + 1) and x.
Therefore, (x + 1)^{2}  x^{2} = 47
x^{2} + 2x + 1  x^{2} = 47
2x + 1 = 47
Therefore, x = 46/2 = 23






10 . 
What is the average of first 25 consecutive odd numbers ?


Answer & Explanation
Answer : Option
D


Explanation : 

Because, Avg of first n consecutive nos. is n.






