If eleven plus two equals one, what does nine plus five equal?

You walk into a room where there are three primates held in their respective cages:
1) A lion who is eating the flesh of a goat.
2) An orangutan who is playing with blocks.
3) A donkey who is sitting idle.

Who is the most intelligent primate in the room?

I don't get anymore wetter, no matter how much rain falls on me.

What common phrase is represented by the below lines

Easy going:
Weak, 'I'm going.'
Tough, 'I'm staying.'

Medium going:
Weak, 'I'm going.'
Tough, 'I'm staying.'

Tough going:
Weak, 'I can't do it, I'm staying!'
Tough, 'Let's get going.'

I cannot talk, but I always reply when spoken to. What am I?

Which fur should we be getting from the Lion?

If an electric train is travelling south, then which way is the smoke going?

A sundial has the fewest moving parts of any timepiece. Which has the most?

Suppose you are sitting in an interview and the interviewee asks you an aptitude question.

You have three buckets with a capacity of 4 litres, 8 litres and 10 litres and you have a large tank of water. Now you have to measure 3 litres of water precisely using those buckets. How will you do it?

2, 3, 5, 9, 17, _ What is the next number in the sequence?