What question can you never answer yes to?

What is always in front of you but can’t be seen?

A brand new Mobile Phone was on sale at 20% as a promotional offer. By what per cent must the Mobile price be increased to sell it at the original price again?

Can you find out the missing number?

? 4 5 3 5

9 5 7 10 3

Outside a massage parlour, there is a board that reads
"I only massage those who do not massage themselves."

Reading the above statement, does the masseur massage himself?

A wealthy man lives alone in a small cottage. Being partially handicapped he had everything delivered to his cottage. The mailman was delivering a letter one Thursday when he noticed that the front door was ajar. Through the opening he could see the man's body lying in a pool of dried blood. When a police officer arrived he surveyed the scene. On the porch were two bottles of warm milk, Monday's newspaper, a catalog, flyers, and unopened mail. The police officer suspects it was foul play. Who does he suspect and why?

When it is alive we sing, when it is dead we clap our hands. What is it?

What 4-letter word can be written forward, backward or upside down, and can still be read from left to right?

A sundial has the fewest moving parts of any timepiece. Which has the most?

There is something which you can be arrested for attempting but not for successfully completing.