Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

There was once a troop of 5 elves. The 5 elves were very dedicated on finding the magical treasure of 1000 coins. However, being elves, they were super geniuses, very greedy and they did not hesitate in taking lives of other elves. The 5 elves were named Aye, Bee, Cee, Dee and Ee, ranked from high to low respectively, from Aye to Ee. One fine day, their efforts brought results and they found 1000 coins. Now they had to split it in between them as per their ranks. The lowest ranked elf has to make the proposal. If the proposal is accepted by majority, it is agreed, or the suggesting elf is killed.

What proposal should elf Ee make ?

That attorney is my brother, testified the accountant.

But the attorney testified he didn't have a brother.

Who is lying?

If there are fifteen crows on a fence and the farmer shoots a third of them, how many crows are left?

A sundial has the fewest moving parts of any timepiece. Which has the most?

What does it mean?

Can you count the number of triangles in the picture below?

Replace the question mark with the correct number.

2 + 2= 4
3 + 3= 18
4 + 4= 48
5 + 5= ?

In a concert, Christina is performing a dance show with her group.
At 10:00, she and her crew were dancing in an absolutely straight line. At that time Christina was standing in 4th position from both the front and back end of the row.

What was the size of her crew?

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