What is more useful when it is broken?

I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

Once while in his court, King Akbar asked Birbal to write something on a wall that makes one sad when read in good times and makes one happy when read in sad times.

He took only a few moment and wrote something that fit the requirements. What did he write?

I am a number I am not an odd number I am higher than 90 I am not higher than 100 If you subtract me from 100, you get nothing. What number am I?

If,

Akriti = 631
Levis = 521
Sroti = 521
Aneel = 533
Then,
Sunil =?

Can you identify the hidden rebus in the image below?

Out of the nine cats that you can see in the picture, there are only two that are completely identical. Can you find them out?

Railroad Crossing, look out for the cars. Can you spell that, without any R's ?

How many times can you subtract the number 5 from 25?

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.