What number should come in place of the question mark below?

If 2 workers can complete painting 2 walls in exactly 2 hours.

How many workers would be needed to paint 18 walls in 6 hours?

Replace the question mark with the correct number, given the pair of numbers exhibits a similar relationship?

? : 3839 :: 11 : 1209

Find The Missing Number In the Sequence.
6 25 64 ? 32 1

I go up and I go down.
I go up towards the beautiful sky and down toward the green ground.
I am present tense.
I am past tense too
Children love me.

Who Am I?

It is deaf, Dumb and Blind!!!

Still, always tells the truth. What is it?

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

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.'

You are in a room that has three switches and a closed door. The switches control three light bulbs on the other side of the door. Once you open the door, you may never touch the switches again. How can you definitively tell which switch is connected to each of the light bulbs?

John was going on a jungle trip. He asked his wife to pack something to eat, something to drink and something to burn if he feels cold in the jungle. When John opens the backpack he found just one thing in the bag. What was it?