I travel all around the world but always stay in the corner. What am I?

Can you solve the below algebraic mathematical equation?

(J+O+I+N+T)3 = JOINT

4 fathers, 2 grand-fathers and 4 sons went to watch the movie.What is the minimum number of tickets they need to buy ?

John and Jenni are a married couple. They have two kids, one of them is a girl. Assume safely that the probability of each gender is 1/2.
What is the probability that the other kid is also a girl?

Hint: It is not 1/2 as you would first think.

Here is what you have to do. You have to throw a ball as hard as you can but it must return back to you even if it does not bounce at anything. Also, you have nothing attached to the ball. There is no one on the other end to catch that ball and throw it back at you.

How will you do it?

In 1990, a person is 15 years old. In 1995, that same person is 10 years old. How can this be?

Only one colour, but not one size,
Stuck at the bottom, yet easily flies.
Present in sun, but not in rain,
Doing no harm, and feeling no pain.
What is it?

The current time can be represented by below textual rebus.

0
=========
B.Sc
LLB

Can you tell us the current time?

On one occasion, A Boy collects 71 rupees in form of 20 paise and 25 paise. He collects a total of 324 coins.

Can you tell me how many 20-paisa and 25-paisa he got?

There is a shop where written:
Buy 1 for $1
10 for $2
100 for $3
I needed 999 and still only paid $3. How could this be financially viable for the shop-keeper?