My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

The first person saw the bridge step on it and crossed,
the second person saw the bridge did not step on it but crossed,
the third person did not see the bridge did not step on it but crossed.
Who are these people?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

Keyboard words are not in alphabetical order, Why?

Can you make four (4) nines (9) equal 100?

Spot the cat in the picture below

Count the Triangle in the figure given below:

Find the next number in the series below

21 32 54 87 131 ?

If a shopkeeper can only place the weights on one side of the common balance. For example, if he has weights 1 and 3 then he can measure 1, 3 and 4 only. Now the question is how many minimum weights and names of the weights you will need to measure all weights from 1 to 1000? This is a fairly simple problem and very easy to prove also.

When does a USA Potato change its nationality?