Find The Next Number In The Sequence

30 10 15 13 0 16 -15 ?

Why did the Girl throw the butter out of the window?

Make eight squares by moving only two matchsticks.
Note- Square can be of different sizes.

A spaceship was lost. The detective was given a piece of paper. This was the location of the spaceship! This is what the slip had scribbled on it:
Juice, Umbrella, Potato, Ice, Tomato, Elephant, Rice.

Where is the spaceship?

Before the start of the car race, John and Jacob have the same amount of fuel in their car. With this fuel, John can drive for 4 hours while Jacob can drive five hours.
After a time they realize that the amount of fuel left in John's car is 1/4th of the fuel in Jacob's.

For how long they are racing?

How many triangles can you find in this given picture?

There is a box full of marbles,
all but two are blue,
all but two are green,
and all but two are red.

How many marbles are in the box?

Find out the number of circles in the given picture having Illusion

John was driving a bus and got stuck when passing through an underpass. Then came Jacob with a needle and got the bus out of the underpass.

What did the boy do?

Below is the sum of symbols in each row and column in the figure. Analyzing the figure, can you find out the value of the symbols?