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

With the help clues provided in the image, can you find the 5 digit key?

When it is alive we sing, when it is dead we clap our hands. What is it?

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?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

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

What am I?

Why 1729 is a magic number? Answer Logically.

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

Count the Triangle in the figure given below:

4 fathers, 2 grand-fathers and 4 sons went to watch the movie.What is the minimum number of tickets they need to buy ?