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

Can you discover the missing number in this series?

37, 10, 82
29, 11, 47
96, 15, 87
42, ?, 15

You are mixing a mixture of cement and Sand with five gallons of water. You have a garden hose giving you all the water you need. The problem is that you only have a four-gallon bucket and a seven-gallon bucket and neither has graduation marks. Find a method to measure five gallons.

Suppose that you are trapped on the surface of a frozen lake. The surface is so smooth and ideal that there is no friction at all. You cant make any grip on the ice and no wind is blowing to help you out. You have just a mobile phone with you which has got no reception disabling you to call for help.

How will you plan your escape before you freeze to death on the frozen lake?

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

Double it and multiply it by 4. Then divide it by 8 and you’ll have it once more. What number is it?

In a box, there is a jumble of 7 red balls, 6 blue balls, 5 green balls, and 4 yellow balls. What is the minimum number of balls, will you have to pick up so that you have at least 4 balls of the same colour?

In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

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.