I am looking for a word that change both gender and number when i add the letter 'S'.

What Word am I Looking For ?

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

Joseph buys three kinds of chocolates for 100 rupees. The first one is priced at 5 rupees, second one at 3 rupees and third one at 0.5 rupees.

If he bought 100 chocolates in total, how many pieces do you think he bought each chocolate?

You are in a room with no metal objects except for two iron rods. Only one of them is a magnet.
How can you identify which one is a magnet?

What has one letter and starts with an E?

What has many teeth, but cannot bite?

How can you tell a raw egg from a hard-boiled egg?

Look at the picture and find out which square is not linked with any of the other squares.

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

Transform the word THINK into BRAIN while changing only one letter at a time in a manner that each of the word in the process is a real word!!!