what does the below rebus means?

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

John had a bag containing colourful marbles. The colours are red, green and blue. The total number of marbles he had in his bag was 60. There are 4 times as many red marbles as green marbles. 6 more blue marbles than green marbles. How many marbles of each colour did John have?

What does it mean?

Can you find out what is missing?

1 3 5
2 4 ?

Hint: It's not six. Think out of the box.

Spot what is wrong here in below Picture?

What demands an answer, but asks no questions

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

What has many keys but can’t open a single lock?

There are 2 cops parked along a one-way street looking for traffic violations. They spot a taxi driver going in the wrong direction, yet they do nothing.

Why?