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

In which direction should the missing arrow point?

What's the only room from which no one can enter or leave

The more of this there is, the less you see. What is it?

The picture shows the dice results in each couple of throws. If they are actually following a pattern, can you find out the missing one?

In the addition below, all digits have been replaced by letters. Equal letters represent equal digits and different letters represent different digits.
ABCABA
BBDCAA
ABEABB
ABDBAA
------- +
AAFGBDH
What does the complete addition look like in digits?

What number divided by 4 is the same as that number minus 4?

In a competitive exam, each correct answer could win you 10 points and each wrong answer could lose you 5 points. You sat in the exam and answered all the 20 questions, which were given in the exam.
When you checked the result, you scored 125 marks on the test.

Can you calculate how many answers given by you were wrong?

While going to your grandmother's house, you counted Twenty houses on the right side. While returning back to your home, you counted Twenty houses on the left side.

How many houses are there between your home and your grandmother's home?

Nine marbles are arranged in the image below. Can you slide two marbles to form a square?