If 21x = 79x, what is the value of x?

In Greek mythology, the Sphinx sat outside of Thebes and asked this riddle of all travellers who passed by. If the traveller failed to solve the riddle, then the Sphinx killed him/her. And if the traveller answered the riddle correctly, then the Sphinx would destroy herself. The riddle:

What goes on four legs in the morning, on two legs at noon, and on three legs in the evening?

Oedipus solved the riddle, and the Sphinx destroyed herself.

Alex is stranded on an island covered in forest.
One day, when the wind is blowing from the west, lightning strikes the west end of the island and sets fire to the forest. The fire is very violent, burning everything in its path, and without intervention the fire will burn the whole island, killing the man in the process.

There are cliffs around the island, so he cannot jump off.

How can the Alex survive the fire? (There are no buckets or any other means to put out the fire)

Solve the equation by replacing the alphabet with numbers.

MOM + MOM + NO = BOOK=

How many triangles can you find in this given picture?

10+10 and 11+11 can give you the same answer.

Explain how?

Find The Next Number in the series:

12 13 15 17 111 113 117 119 123 ?

What 5-letter word typed in all capital letters can be read the same upside down?

Prove that twice of ten is the same as twice of eleven.

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?