Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

What is harder to catch the faster you run?

Make a sentence consisting of three words that have the whole alphabet.

You have two bottles of pills marked with labels A and B. The pills are identical. The doctor has asked you to take one A pill and one B pill daily. You cant take more or less than that.

While taking out the pills one day, you took out one pill from A and by mistake took out two from B. You have no idea which pill is which now.

You cant throw away the expensive pills. What will you do now?

Aaron, Brad, Christopher, Danny and Elvis decided to play a game of tiddlywinks. In this game they decided that one win will get 1 point for winning, 0 for losing and 1/2 in case of a tie.

They finished the game in alphabetical order and it was found that the scores were different for each person.

Based on the following two statements, can you find out the result of the individual games?
Brad: No one could finish like me, without a loss.
Elvis: No one played worse than me, I finished without a single win.

I get hot but I never sweat,
I cook food but I am not a chef,
I have a door but you can't enter me,
I have a light but I am not a lamp.
Who am I?

What has a bottom at the top?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

I shave every day, but my beard stays the same. What am I?