How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

Complete the following series. It.s very logical:

1, 4, 5, 6, 7, 9, 11, __?

Two guards were on duty outside a barracks. One faced up the road to watch for anyone approaching from the North. The other looked down the road to see if anyone approached from the South. Suddenly one of them said to the other, "Why are you smiling?"

How did he know his companion was smiling?

What is black when you buy it, red when you use it, and gray when you throw it away?

Spot what is wrong here in below Picture?

Different lights make me strange by changing me into different sizes. What am I?

Buy me, smell me or deliver me, I do not change.

Who am I?

Bopanna was working on a murder case when he received a message about the location of the murder weapon.
The message was encrypted as below.

"deb mitciv eht edisni neddih si nopaew redrum ehT"

Tell me the location of the murder weapon.

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

Can you spot what's wrong with the following sentence?

PETER WAS ANGRY AT
HIMSELF BECAUSE HE
ACCIDENTALLY LEFT THE
THE KEYS TO HIS CAR
AT HIS FRIEND'S HOUSE.