Which number should replace the question mark?

How many words can a pen with half refill write?

Look at the picture and find out which square is not linked with any of the other squares.

What kind of band never plays music?

What goes up but never comes down?

While handling a project, the landscaper is asked by the owner of the mansion that he wants four trees in front of his mansion that are exactly equidistant from each other.

How will he do it?

In a supermarket, there is an intelligent glass pane before a refrigerating unit. This glass pane allows cherries and apples through it but does not allow grapes and Orange to pass through it.

Can you identify the rule that the glass pane is following?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Can you identify the famous TV character from the rebus below?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?