If eleven plus two equals one, what does nine plus five equal?

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

What Word am I Looking For ?

People make me, save me, change me, raise me. What am I?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

Move three sticks of the spiral below to form a square.

If Rajina's daughter is my daughter's mom, who am I to Rajina?

Jigsaw captured 100 people and make them stand in a circle and all these people are labelled as Person1, Person2, Person3... Person100. He made them play a crazy game in which Person 1 shot Person 2 and pass the gun to the next person and so on until one stands alive.

Which person will survive in the end?

2 ladies and 2 girls need to cross a river in a boat big enough for 1 LADY or 2 girls. How do they do it?

We have four gears with below features=> Both Gear A and D has 60 teeth=> Gear B has 40 teeth=> Gear C has 20 teeth=> Every two minutes, Gear B makes 25 full turns.What is the relative speed of Gear A and Gear B?

What begins with T, ends with T, and has T in it?