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

Place a mathematical symbol between the numerals 5 and 9 in such a way that the resulting number is greater than 5 but smaller than 9.

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

Manish and Manoj play 5 games of chess.
Both Manish and Manoj win the exact same number of games. There is no tie at all.

How?

On a windy rainy night , I was driving in my car.
When i reach the bus stand , i see three people waiting for the bus.

1. An old lady who needs an immediate medical attention
2. My Best Friend
3. Girl whom i love from childhood

My car is a two seat, so can you tell me , what i have done in this situation ?

I’m tall when I’m young, and I’m short when I’m old. What am I?

If,

A = 1

B = 2

C = 3

...

...

Z = 26.

Based on above rule, you need to find an eleven letter word whose letter sum is equal to 52.

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

What work can one never finish?

Why 1729 is a magic number? Answer Logically.