here are the answers....
1.. The man is very, very short and can only reach
halfway up the elevator buttons. However, if it is
raining then he will have his umbrella with him and
can press the higher buttons with it.
2.. The surgeon was his mother.
3.. It was daytime.
4.. At the time she went into labor, the mother of the
twins was travelling by boat. The older twin, Terry,
was born first early on March 1st. The boat then
crossed a time zone and Kerry, the younger twin, was
born on February the 28th. Therefore, the younger twin
celebrates her birthday two days before her older
brother.
5.. A square manhole cover can be turned and dropped
down the diagonal of the manhole. A round manhole
cannot be dropped down the manhole. So for safety and
practicality, all manhole covers should be round.
6.. The poison in the punch came from the ice cubes.
When the man drank the punch, the ice was fully
frozen.
Gradually it melted, poisoning the punch.
7.. They were two of a set of triplets (or
quadruplets, etc.).(This puzzle stumps many people.
They try outlandish solutions involving test-tube
babies or surrogate mothers. Why does the brain
search for complex solutions when there is a much
simpler one available?????)
8.. The man had hiccups. The barman recognized this
from his speech and drew the gun in order to give him
a shock. It worked and cured the hiccups-so the man no
longer needed the water. (This is a simple puzzle to
state but a difficult one to solve. It is a perfect
example of a seemingly irrational and incongruous
situation having a simple and complete explanation.
Amazingly this classic puzzle seems to work in
different cultures and languages.)