You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

Count the number of triangles in the below picture?

Two prisoners Jack and Jill are locked in a cell.
There is open window approx 40 feet above the ground of the cell.
They are never able to reach there.

Then they plan to escape by a tunnel and they start digging out.
After digging for more than 20 days, Jill comes with the different plan and they escaped.

what was the plan ?

When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

Take one out and scratch my head, I am now black but once was red. What am I?

At my favorite fruit stand,
an orange costs 18,
a pineapple costs 27,
and a grape costs 15.
Using the same logic, can you tell how much a mango costs?

You and your two friends are working in a multinational company. How can you three find out the average salary of you all without disclosing your own salary to the other two?

Can you identify the Oscar-winning movie from the rebus below?