A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

What Time Should the last watch show in the below figure?

Can you make numbers like 24, using numbers 3,3,7 & 7 with any arithmetic operator?

What has hands, but can’t clap?

Find the Odd One Out?
84129
32418
47632
36119
67626
72927

Find the mistake in the below maths equations

A = 2
A(A-1) = 2(A-1)
A2-A = 2A-2
A2-2A = A-2
A(A-2) = A-2
A = 1

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!!!

Buy me, smell me or deliver me, I do not change.

Who am I?

John killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?