Which Number is the odd one out?

A) 7145
B) 2716
C) 5321
D) 4135

A boy collects white seashells from the sea and brings them home every night. When he has enough of them, he decides to sell them to a trader.

The trader is ready to buy the shells and he asks the boy about the quantity. At this, the boy starts calculating. He has a giant box that contains 3 mini boxes. Two of them have another mini box inside. If the giant box can hold 50 shells, how many brown shells can he sell to the trader?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

A bomb exploded in a room full of married couples and no one died. How?

What is common among 11, 69, and 88?

What numbers should go on the bottom line?
3 6 9 15
8 2 10 12
11 8 19 27
19 10 29 39
? ? ? ?

What is the fastest way to double your money?

What is black when you buy it, red when you use it, and gray when you throw it away?

In a family supper, a grandfather, a grandmother, two fathers, two mothers, four children, three grandchildren, one brother, two sisters, two sons, two daughters, one daughter-in-law, and one mother-in-law need to sit at a table.

There are only seven chairs available at the place. How many more chairs do they have to borrow so that everyone can sit down together for the suppers if everybody requires a separate chair?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?