Can you convert the number zero(0) into a positive number using just one mathematical operator ?

Can you move 2 matchsticks to form four equal sized squares.

There is a jar in which there are two types of candies.
20 blueberries and 16 strawberries. You perform the following steps:
1) You take out two candies.
2) If the two candies are of the same flavour, you add a blueberry one otherwise, you add the strawberry one.

You repeat these two steps till there is just one candy remaining in the jar. Which flavoured candy will be left?

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).

Count The number of F's in the paragraph below:

"FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS"

I have a five and a three-gallon jar. Assuming there is an infinite supply of water, how can I measure one-gallon water?

What does this rebus means ?

In the image below, can you find the value of an angle(y)

What is the next shape from answers A, B, C, and D figure?

Which number should replace the question mark?