Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

There are seven sisters in a house in a village where there is no electricity or any gadget.

Sister-1: Reading Novel
Sister-2: Cooking
Sister-3: Playing Chess
Sister-4: Playing Sudoku
Sister-5: Washing clothes
Sister-6: Gardening

what is Sister-7 doing ?

Can you count the number of matches in the picture below ?

Four men were in a boat on the lake. The boat turns over, and all four men sink to the bottom of the lake, yet not a single man got wet! Why?

If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?

The barber of Town shaves all men living in the town. No man living in the town is allowed to shave himself. The barber lives in that town. Who then shaves the barber of the town?

What is at the end of a rainbow?

What does the below image rebus riddle means ?

A man says, "Brothers and sisters, have I none, but that man's father is my father's son." Who is that man?

You see me once in June, twice in November, and not at all in May. What am I?