Why Aeroplane windows are round?

ENEMY = 2 * LINK
LINK + 2 = HELL

Then what will be TAXI + HELL? Select from the options below:
a) ROTTEN
b) DANGER
c) HEAVEN
4) MORTAL

I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?

What two things can you never eat for breakfast?

Prove that the below maths equation is true.

8 + 8 = 91

After undergoing a successful eye operation, A blind girl has just boarded a train to her home. The doctor asked her to open the bandages after 3 hours. On her train journey, she opened the bandages and within a fraction of the time she commits suicide by jumping off the train.

Though her operation was successful, Why did she commit suicide?

That attorney is my brother, testified the accountant.

But the attorney testified he didn't have a brother.

Who is lying?

I am a type of room you cannot enter or leave. Raised from the ground below, I could be poisonous or a delicious treat. What am I?

Can you find out the next digit in the following series ?

0, 0, 1, 3, 2, 6, 3, 9, 4, 12, 5, ?

Replace the question mark with the number below given a simple math problem.