Can you find out the remainder when 3^300 is divided by 5?

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?

Which alphabet letter is a question?

Different lights make me strange by changing me into different sizes. What am I?

What number does the below three word/phrase identify and why?
1. Deck
2. Year
3. Singing in the Rain

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

Its something that each of us devours,
Not just us but birds, beats, trees, and flowers,
Frets iron and nibbles steel,
Toil hard stones to meal,
Exterminates king, collapse town,
And blows the mountains down.

You have three orange, two pink and five purple balls in the drawer beside your bed. There is no electricity and the room is entirely dark. How many balls must you take out to ensure at least one ball of each colour at least?

Find the next number in the following series:
6, 14, 26, 98, __?

I make two people out of one. What am I?