Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Can you find the key in the picture below?

Solve The below Equation:

ALFA + BETA + GAMA = DELTA

Where do fish keep their money?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

You need to remove four matchsticks from the picture below and still need to maintain the following as in the original image.
1. 1st row contains 12 matchsticks
2. 2nd row contains 12 matchsticks
3. 1st column contains 12 matchsticks
4. 2nd column contains 12 matchsticks

John can eat 27 chocolates in an hour, Jacob can eat 2 chocolates in 10 minutes, and Jolly can eat 7 chocolates in 20 minutes. How long will it take them to share and eat a box of 120 chocolates whilst playing Chess?

Why is it against the law for a man living in Delhi to be buried in Mumbai?

Three fair coins are tossed in the air and they land with heads up. Can you calculate the chances that when they are tossed again, two coins will again land with heads up?