Aptitude and Reasoning Questions

It is given that efficiency ratio =3:1

so time ratio will be 1:3 (since work is same)

Also given that time diff = 32 days. ratio difference = 3-1 =2 

2 ratio = 32 days

1 ratio = 16 days.

So A will alone finish it in 16 days and B will finish it in 16*3 = 48 days.

Total work = LCM of 16 and 48 = 48.

Total time = Total work/Total efficiency 

ie; 48/4= 12 days.

The first  is produced by the second.

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

Let X be the event that cards are in a club which is not king and other is the king of club.
Let Y be the event that one is any club card and other is a non-club king.
Hence, required probability:
=P(A)+P(B)

=12C1*1C152C2+13C1*3C152C2

=12*252*51+13*3*252*51= 24+7852*51 = 126

Let Kumar’s present age be "x" years and Sailesh’s present age be "y" years.
Then, according to the first condition,

x - 10 = 3(y - 10) => x - 3y = - 20 ........(1)

Now, Kumar’s age after 10 years = (x + 10) years.

Sailesh’s age after 10 years = (y + 10) years.

(x + 10) = 2 (y + 10)  => x - 2y = 10 ......(2)

Solving (1) and (2),

we get x = 70 and y = 30

Kumar’s present age = 70 years    and  Sailesh’s present age = 30 years.

We feel uncomfortable in hut and humid climate because in hot weather, body sweats more but due to high humidity, this sweat does not evaporate easily.