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

What Word am I Looking For ?

How many triangles are there in the picture below?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

Remove two matchsticks to make the below equation correct.

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!!!

Can you write down eight eights so that they add up to one thousand?

Replace the 'X' with any mathematical symbol to make the expression equal to 111.

18 X 12 X 2 X 3 = 111

The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?