How many triangles can you find in this given picture?

Suppose you are sitting in an interview and the interviewee asks you an aptitude question.

You have three buckets with a capacity of 4 litres, 8 litres and 10 litres and you have a large tank of water. Now you have to measure 3 litres of water precisely using those buckets. How will you do it?

In a mathematical quiz, you are asked the following question:

Use three 9s in a mathematical expression without dividing or multiplying to form the number one.

Can you answer the question?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

What demands an answer, but asks no questions

Count the number of triangles in the below picture?

In this image, you can see three almost identical Doraemon images. Can you spot the odd one out from them?

using four eights (8) and a one (1) and one mathematical symbol , create the number 100

What always comes into a house through the keyhole?

If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?