Why is 6 afraid of 7?

Why is a river so rich ?

You find yourself in a strange place guarded by two guards.One of the guard always say truth while other always lies.You don't know the identity of the two.You can ask only one question to go out from there. What should you ask?

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

You have two hour glasses one measures 7 minutes and the other measures 4 minutes.
Using these two-hour glasses, you need to measure exactly 9 minutes.

How come?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

What does this rebus puzzle means ?

John and Jacob are planning on a vacation. John says, "It will be better if we take the train to the hotel. We will reach faster."
To this, Jacob says, "No. You are wrong. The train stops halfway to the hotel and then we will have to walk the rest of the way. We should take the bikes to the hotel directly."
John says, "You are wrong."

Now, John takes the train while Jacob takes the bike. The train travels at four times the speed of the bike. The bike travels at twice the speed of walking.

Who do you think will reach the hotel first?

In the image below, can you find the value of an angle(y)

Two old friends, Jack and Jill, meet after a long time, and discussing as:

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?