Four persons can cross a bridge in 3,7,13,17 minutes.Only two can cross at a time.Find the minimum time taken by the four to cross the bridge ?

For the input "A rolling stone gathers no moss", the steps followed are:

Step 1: rolling A stone gathers no moss

Step 2: rolling stone A gathers no moss

Step 3: rolling stone gathers A no moss

Step 4: rolling stone gathers no A moss

After 4 steps the fifth word is "A".

Given there are 2 coloured socks, which is black and White
Let suppose 3 is choosen at random
then three conditions arises
1. all are black
2.all are white
3. either it will have 2 black and 1 white or it will have 2 white and 1 black
so in all the conditions as above mentioned we are getting atleast one pair of socks.

So, he must take out 3 to be sure that he has a matching pair.

Spouse means a person's partner in marriage, it can be male or female.
But given F is spouse of B
And P is Son in law of N
Relation between F and B
Relation between P and A only
and p is male So, A must be female
=> B is male child.

let x be the correct answer and y be the wrong answer
so the total number of questions is (x + y) = 150.....(1)
=> 4x - 2y = 420.....(2)
By solving (1) & (2), we get
=> 6x = 720
hence x = 120
Therefore, number of correct answers are 120.