If two's company, and three's a crowd, then whats four and five ?

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

Find the number of squares in the below-given picture.

There is a shop where written:
Buy 1 for $1
10 for $2
100 for $3
I needed 999 and still only paid $3. How could this be financially viable for the shop-keeper?

The following alphametic has only one solution. Can you find it?
ENLIST + SILENT + LISTEN = ANAGRAM

PS: You may start the number from 0.

You board a train. The train will have to enter a tunnel soon. You are claustrophobic. Which place is the best for you to sit?

What is common among 11, 69, and 88?

Suppose we lay down two cups in front of you. One of the cups is filled with tea and the other one with coffee. Now we ask you to take a spoonful of tea and mix it with the coffee. At this moment, the coffee cup has a mixture of tea and coffee. You have to take that mixture (spoonful) and add it back to the tea.

Can you now tell if the cup of coffee has more tea or the cup of tea has more coffee?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

Which alphabet letter is a question?