Brain Teasers

1. Classic puzzle: There is a river. On one side a man is standing with
a tiger, a goat and a bunch of grass. The tiger can kill the goat and
the goat can eat the grass, when left alone. However, they are all safe
when the man is present.

The man has to transport each of them to the other side of the river on
a boat. Now the boat can carry one item at a time along with the man. How
will he do it and keep them all safe?

2. Mall puzzle: There is a big shopping mall and it has 4 gates (let's name
them as gate A, B, C and D). Every time you come inside the big shopping
mall, you have to pay Rs. 5 and every time you leave it, you again have
to pay Rs. 5. Also unlike most shopping malls, whatever amount of money
you carry with you inside, it doubles! For example if you carry Rs. 5,
it will become Rs. 10.

You have to go inside the mall through gate A, come out of B, again go
inside through gate C and finally come out of gate D. Now, how much
money should you carry inside the mall so that when you finally come
out of the gate D, you should be left with no (zero amount) money?

3. A few quick ones: 
. Larry's father has five sons named Ten, Twenty, Thirty, Forty... Guess
what would be the name of the fifth?
. You have 20 apples in a basket. 20 children come to you and each
one of them asks for an apple. You want to give an apple to each
one of them, but still keep one inside the basket? How will you do it?
. Name all the numbers from 1 - 100, which have the letter 'A' in
their spellings?