Mr Black, Mr Gray, and Mr White are fighting in a truel. They each get a gun and take turns shooting at each other until only one person is left. Mr Black, who hits his shot 1/3 of the time, gets to shoot first. Mr Gray, who hits his shot 2/3 of the time, gets to shoot next, assuming he is still alive. Mr White, who hits his shot all the time, shoots next, assuming he is also alive. The cycle repeats. If you are Mr Black, where should you shoot first for the highest chance of survival?

What goes through cities and fields, but never moves?

An express train takes 3 seconds to enter the tunnel which is 1 km long.
If it is travelling at 120 km an hour, how long will it take to pass completely through the tunnel?

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

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

Why is a river so rich ?

I can turn polar bears white.
I can make anyone dance.
I can make everyone cry
I can make your hands clap
I can make you thin.
I can make you smile.
I can make you smile

Can you guess the riddle?

Which number should replace the question mark?

The dirtier I get, the whiter I look. Who am I?

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