Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Jenifer is learning to drive her car. She went down a one way lane and in the wrong direction. But she do not break any law.

How come ?

A rubber ball keeps on bouncing back to 2/3 of the height from which it is dropped. Can you calculate the fraction of its original height that the ball will bounce after it is dropped and it has bounced four times without any hindrance ?

Using eight eights and addition only, can you make 1000?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

A mile-long train is moving at sixty miles an hour when it reaches a mile-long tunnel. How long does it take the entire train to pass through the tunnel?

Can you place six X (crosses) in below board without making three in a row in any way ?

Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

You are given a cube that is made with the help of 10x10x10 smaller cubes summing up to a total of 1000 smaller cubes. You are asked to take off one layer of the cubes.
How many remain now?