They are the five precious gems of an everyday sort and all can be found on a Tennis Court. Who are they?

Name a key which is hardest to turn.

A bank customer had $100 in his account. He then made 6 withdrawals. He kept a record of these withdrawals, and the balance remaining in the account, as follows:

Withdrawals Balance left
$50 $50
$25 $25
$10 $15
$8 $7
$5 $2
$2 $0
----- -----
$100 $99

Why are the Totals not tallying?

What do you think with the below Picture ?

Which flower has two lips?

Prove that twice of ten is the same as twice of eleven.

What has many teeth, but cannot bite?

What can you see in the middle of March and April that you can never see in any other month?

What is both possible and impossible at the same time?

Why do people go to bed?