You are presented with three boxes. One of them has a red ball inside and the other two have a black ball inside each of them. You are asked to pick up the one with red ball and you pick one. Now, one of the other boxes is opened and it is found to have a black ball.

You are presented with a chance to change your box with the one that is left closed. Will you change your box? Why or why not?

You can hear me, but you can't touch or see me.

What am I?

How far can you walk into the woods?

If,

A + B = C
D - C = A
E - B = C

Based on the above equations, find out the answer for:

D + F = ?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

Find the next number in the series below.

6 18 270 72090 ?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

I have branches, but no fruit, trunk or leaves. What am I?

Replace the question mark with the correct number in below Picture:

Two old friends, Jack and Bill, meet after a long time.

Three kids
Jack: Hey, how are you, man?
Bill: Not bad, got married and I have three kids now.
Jack: That's awesome. How old are they?
Bill: The product of their ages is 72 and the sum of their ages is the same as your birth date.
Jack: Cool..But I still don't know.
Bill: My eldest kid just started taking piano lessons.
Jack: Oh, now I get it.

How old are Bill's kids?