I am a seven-letter word but if you remove four of my letters I will have one left. What word am I?

What has hands, but can’t clap?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

What is a word made up of 4 letters, yet is also made up of 3. Sometimes is written with 9 letters, and then with 4. Rarely consists of 6, and never is written with 5.

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

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

Who am I?

Why despite killing dozens of people Charley and Wilma were not punished?

If an electric train is travelling south, then which way is the smoke going?

Can you count the number of lines in the below picture?