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

What Word am I Looking For ?

I am white when I am dirty, and black when I am clean. What am I?

I look at you, you look at me, I raise my right, you raise your left. What am I?

A Scientist was fifty years old in the year 2000 but he was forty years old in the year 2010. How can this be possible?

PS: It has a logical answer.

He does not have any heart but still, He manages to live.
If you kill him, you will eventually die but yet you kill him.
He cannot run, who is He?

How many triangles can you count in the figure given?

Can you count the number of triangles in the given figure?

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

A small town is visited by an ice-cream truck every day. On the first day of February, the truck visits as usual and 5 children, one from each of the first 5 houses on the street buys an ice cream that is of the different flavor from each other along with a completely different topping.

Go through the details below and find out which child lives in which house and bought which ice-cream flavor with which topping:

1. Jim lives between the child who bought the Raspberry topping and the child who bought mango ice cream.

2. Joyce, whose house has an even number, bought the cherry topping. Nancy does not live next to Joyce.

3. The blackcurrant ice cream had no topping.

4. The child who lives in house number 2 had the butterscotch ice cream. The child in house number 3 did not have chocolate ice cream.

5. Mike had banana ice cream. He hates banana cherry.

6. The child who had the cashew topping lives in house number 5. Dustin does not live in house number 4.

Please note that the odd numbered houses and the even numbered houses are located on the exactly opposite sides of the street.

A King wants to send the diamond ring to his girlfriend securely. He got multiple locks and their corresponding keys. His girlfriend does not have any keys to these locks and if he sends the key without a lock, the key can be copied in the way. How can King send the ring to his girlfriend securely?