using four eights (8) and a one (1) and one mathematical symbol , create the number 100

What has 13 hearts but no other organs?

You throw me out when you want to use me and you take me in when you don't want to use me.

Who Am I?

Which English verb becomes past tense just by rearranging the letters?

Next Number in the Series,

5, 16, 49, 104, ?

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

I am green and found in the forest and have needles instead of leaves. What am I?
Hint 1: It can be used for Christmas decorations.
Hint 2: I have a strong, scent that is used in air fresheners.

Can you think of a smallest +ve number such that if we shuffle the digits of the number, the new number becomes double the original number?

I welcome the day with a show of light, I stealthily came here in the night. I bathe the earthy stuff at dawn, But by noon, alas! I'm gone.

In a box, there is a jumble of 7 red balls, 6 blue balls, 5 green balls, and 4 yellow balls. What is the minimum number of balls, will you have to pick up so that you have at least 4 balls of the same colour?