You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

By using all numbers, i.e. 123456789 and subtraction/addition, operators number 100 can be formed in many ways.
Example: 98 + 7 + 6 - 5 - 4 - 3 + 2 - 1 = 100

But if we add a condition use of the number 32 is a must. Then there are limited solutions.
One of such solution is: 9 - 8 + 76 + 54 - 32 + 1 = 100

Can you tell me any other solution?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

Before Mount Everest was discovered, what was the highest mountain in the world?

Can you find out a way through which you can make five squares out of the given figure by moving just six match sticks?

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

What is the centre of gravity?

What is wrong in the below Picture?

Use the digits from 1 up to 9 and make 100.

Follow the rules.
=> Each digit should be used only once.
=> You can only use addition.
=> For making a number, two single digits can be combined (for example, 4 and 2 can be combined to form 42 or 24)
=> A fraction can also be made by combining the two single digits (for example, 4 and 2 can be combined to form 4/2 or 2/4)

Question: how can we do this?