Can you count the number of triangles in the given figure?

I have one of the three numbers: 1, 2, or 3 in my mind. I speak only truth. You can ask me just one question for which I will only reply in yes or no or don't know. What question will you ask from me so that you are able to know the number?

If your uncle’s sister is not your aunt, what relation is she to you?

Why is Saturday stronger than Monday?

What you cannot hold but it is yours?

A shepherd had 18 sheep, out of which, all but ten died.

Can you tell us how many sheep was he left with?

All of the flowers I have are orchids except two. All of the flowers I have are hibiscuses except two. All of the flowers I have are roses except two.

Can you tell me how many flowers I have?

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?

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

A red house is made out of red bricks. A yellow house is made out of yellow bricks. And, a blue house is made out of blue bricks. So, what is a greenhouse made of?