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

What Word am I Looking For ?

Write the next letter in this sequence.
O, T, T, F, F, S, S, E, __
**Hint: It is a Number Series Puzzle

What is more useful when it is broken?

2, 3, 5, 9, 17, _ What is the next number in the sequence?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

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!!!

On a certain day, John celebrated his birthday. Two days later, his older twin brother Jacob celebrated his birthday.

Is this even possible? How can it be?

In the figure, you can see nine stars. What you have to do is connect all of them by using just four line and without lifting your hand i.e. in a continuous flow.

There was a greenhouse.
Inside the greenhouse, there is a white house.
Inside the white house, there is a red house.
Inside the red house, there are lots of babies.

What is It?

Solve the puzzle by telling what does below picture means.