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

Find The Next Number in this series.
1, 2, 6, 42, 1806 ?

You have a square. What you have to do is cut and reassemble the square such that you create a Red Cross sign that has the same volume as that of the square.

You are stuck on an island where you have nothing. You find four pieces of paper somewhere on the island. What will be your strategy to escape from the island safely?

PS: No other resource is available to you on the island, neither can you build anything.

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

Quickly Solve this riddle

7 - 4 + 3 * 0 + 1 = ?

Find the next number in the series.
1 10 24 43 67 ?

A mathematics teacher took exams for his students. Out of the total students, 25% passed both the tests included in the exam. However, only 42% were able to clear the first test.

Can you find out the percentage of those students who passed the first test and also passed the second test?

Eight of us go fourth, not back, to protect our king from an attack. What are we?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?