What work can one never finish?

This is a famous paradox which has caused a great deal of argument and disbelief from many who cannot accept the correct answer. Four balls are placed in a hat. One is white, one is blue and the other two are red. The bag is shaken and someone draws two balls from the hat. He looks at the two balls and announces that at least one of them is red. What are the chances that the other ball he has drawn out is also red?

Can you count the number of triangles in the picture below?

Alex opened 24 presents
Jonah opened 8 presents
Clara opened 1 present

Can you find out how many presents were opened by Candy?

How is the moon similar to a dollar?

What has to be broken before you can use it?

Can you name an animal whose killing cannot be performed without spilling your own blood?

How many letters are in the alphabet?

I am the beginning of everything, the end of everywhere. I'm the beginning of eternity, the end of time and space. What am I?

Count the number of triangles in the given picture.