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

If we add four times the age of John four years from now to five times his age five years from now we get ten times his current age.

How old will John be two years from now?

In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?

There is a shop where written:
Buy 1 for $1
10 for $2
100 for $3
I needed 999 and still only paid $3. How could this be financially viable for the shop-keeper?

What does a man do only once in his lifetime, but women do once a year after they are 29?

Sahir enters the bank aims to rob and finds Jai standing inside armless. He aims a gun at him and asks him the code for the safe. Jai says, 'The code is different every day but if you hurt me, you will never get to know the code'.

Sahir pins him down and ties him with a rope. He then inserts the safe code and easily takes all the money with him.

How did he know the code?

Find the Next Number in the Sequence

2 9 3 1 8 4 3 6 5 7 ?

On one occasion, A Boy collects 71 rupees in form of 20 paise and 25 paise. He collects a total of 324 coins.

Can you tell me how many 20-paisa and 25-paisa he got?

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.

Can you find the largest Three-digit number whose sum is 14 and whose square is less than 5,00,000?