Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

A boy and a girl are sitting on the porch.
"I'm a boy," says the child with black hair.
"I'm a girl," says the child with red hair.
If at least one of them is lying, who is which?

What does Alexander the Great and Winnie the Pooh have in common?

I’m orange, I wear a green hat and I sound like a parrot. What am I?

Find three numbers such that When we multiply three numbers, we will get the prime numbers. The difference between the second and the first number is equal to the third and second.

Which is the correct shadow of the bird?

Consider all the numbers between 1 and 1 million. Among all these numbers, there is something very special about the number 8 and the number 2202. What is it?

If eleven plus two equals one, what does nine plus five equal?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

Find the next number in the series?
2, 12, 36, 80, 150, 252, 392, _ ?