If two's company, and three's a crowd, then whats four and five ?

What does this rebus puzzle means ?

I am a three digit number.
My tens digit is five more than my ones digit.
My hundreds digit is eight less than my tens digit.
What number am I?

John was working on a Chemical Mixture whose weight comprise 90% liquid and 10% solid. The total weight of the mixture is 20 pounds. After a while, John noticed that some of the liquid evaporated and now the liquid comprises just 50% of the weight.

What is the weight of the chemical mixture now?

'Ferrari driver' easily beats the 'force driver' in a two-car race. How did Indian newspapers truthfully report so to look as a 'force drive' had outdone the 'Ferrari driver'? Think!!!

A 52% bias toss for head using the 51% tail bias coin was done to obtain a fair result.

Can you find how bias is the floor in this case?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

I have 50 feet long of cloth, I need to create 50 handkerchiefs each size of 1 foot. I take one minute to cut a 1-foot handkerchief. So how long will it take to cut 50 handkerchiefs?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?