What is the Surname of Barbie Doll?

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 does the below math rebus puzzle mean?

What does the below image rebus riddle means ?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

There are five people. One of them shot and killed one of the other five.
We know following clues:
1. Dan ran in the NY City Marathon yesterday with one of the innocent men.
2. Mike consider being a farmer before he moved to the city.
3. Jeff is a top notch computer consultant and wants to install Ben new computer next week.
4. The murderer had his leg amputated last month.
5. Ben met Jack for the first time six months ago.
6. Jack has been in seclusion since the crime.
7. Dan used to drink heavily.
8. Ben and Jeff built their last computers together.
9. The murderer is Jack's brother. They grew up together in Seattle.

Consider yourself to be a famous detective "Sherlock Homles", Can you find the killer?

Can you find out the missing number in the grid?

Can you find the thief by just looking at the picture below?

There are nine letters in the below-given diagram. You have to form a nine-letter word using these letters.

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