Find out the number of circles in the given picture having Illusion

How many words can a quill made with the feather of a pigeon write with a 100ml bottle of black ink?

What time is it when an elephant sits on a fence?

I want to fill my bucket using both cold and hot water.
I have two taps for both cold and hot water. The hot water tap fills the bucket in exact 6 hours and the cold water tap fills the bucket in exact 4 hours.
I turn both of them simultaneously but I forgot to turn off another tap which removes the water out of the bucket. This tap can empty the bucket in 12 hours.

How Long will it take to fill the bucket?

Can you find the key in the picture below?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

What is next number in the pattern below:

131 517 192 123 ?

What word does this rebus represent?

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What does this Rebus Picture means ?

I am never scared but became petrified and can’t live in a house but would die to make one. What am I?