Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Jack have ten pairs of black socks, eight pairs of white socks and seven pairs of green socks. Everything is mixed in a draw. As there is no light he were not able to identify the colour of the socks. How many of the socks did he want to take to match one pair

Below, you can see three complete equations and one incomplete. Based on the three complete ones, can you complete the incomplete one?

5 $ 4 $ 3 $ 9 = 4215
6 $ 9 $ 2 $ 6 = 3816
4 $ 7 $ 3 $ 3 = 1122
7 $ 2 $ 7 $ 4 = ____

I have branches, but no fruit, trunk or leaves. What am I?

Replace the question mark in the picture below.

You need to pick one entry from pot A and one from pot B to have a perfect match. Can you do it?

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

Prove that the below maths equation is true.

8 + 8 = 91

When it's bad luck to meet a black cat?

Rob is taller than Edwin, and Jurgen is shorter than Rob.
Of only one of the following statements, we now certainly know it is correct:

A.Edwin is taller than Jurgen
B.Jurgen is taller than Edwin
C.It cannot be determined if Jurgen or Edwin is the tallest.