Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

You stand in front of two doors. A guard stands next to each door. You know the following things: one path leads to paradise, the other leads to death. You cannot distinguish between the two doors. You also know that one of the two guards always tells the truth and the other always lies. You have permission to ask one guard one question to discover which door leads to paradise. What one question would you ask to guarantee you enter the door to paradise?

What am I?

Can you make a six-letter word using the letters N, A and B ?

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

Given that

(78)^9 = 6
And (69)^4 = 11

Can you find out

(99)^2 =?

(Note: This is Logical, not Mathematical)

One is to three as three is to five and five is to four and four is the magic number.
What is the pattern?

By what process could you make a 'Tea-Table' into food?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

Count the Triangle in the figure given below: