Why do we preferably have round manhole covers and not square ones?

Who has married many women but was never married?

What has 13 hearts but no other organs?

Take 9 from 6, 10 from 9, 50 from 40, and leave 6.

How Come ??

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

I have a big mouth and I am also quite loud! I am NOT a gossip but I do get involved with everyone's dirty business.

The Federal bank of London is abducted by the robbers. The head of the robbers asked the cashier to empty their money vault to them and when suddenly cashier got a call from her father. To avoid any suspicion, the robber asked the cashier to pick the call and reply her father in the shortest manner possible.

The cashier told her father "Is there an emergency father, Call me when you are free and I will help you in your furnishing" and then the cashier hung up the phone.

After 10 minutes, police arrived at the crime scene.

How did the police know about the robbery?

Do You See It?

What does this rebus riddle mean?

I am quite hot but become too cold if you remove the first two letters. What am I?