Can you circle exactly four of these numbers such that the total is twelve?

1 6 1
6 1 6
1 6 1
6 1 6

What can you hold in your right hand, but never in your left hand?

What has many teeth, but cannot bite?

Can you find the mistake in the below statement?

Count the number of triangles in the given picture.

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

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?

The ages of a father and son add up to 66.
The father's age is the son's age reversed.
How old could they be?
(3 possible solutions).

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

2 ladies and 2 girls need to cross a river in a boat big enough for 1 LADY or 2 girls. How do they do it?