In which direction should the missing arrow point?

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

I have two coins.
* One of the coins is a faulty coin having a tail on both sides of it.
* The other coin is a perfect coin (heads on side and tail on other).

I blindfold myself and pick a coin and put the coin on the table. The face of the coin towards the sky is the tail.

What is the probability that another side is also tail?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

You bought me for dinner but never eat me. What am I?

Nodes are shown below and you need to connect them based on the following rule: Every node can be connected to the number of nodes inside them, i.e. the first node there is a value of 1 which indicates that the first node can connect to exactly one node only.Can you do it?

It can't be seen, can't be felt, can't be heard, and can't be smelt.
It lies behind stars and under hills, And empty holes it fills.
It comes first and follows after, Ends life, and kills laughter.
What is it?

What has one letter and starts with an E?