When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

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?

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

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

I possess a head

I flaunt a tail

But I don't have mouth or legs

Can you find out who I am?

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

Can you write down eight eights so that they add up to one thousand?

Why 1729 is a magic number? Answer Logically.

Count The number of F's in the paragraph below:

"FINISHED FILES ARE THE RESULT OF YEARS OF SCIENTIFIC STUDY COMBINED WITH THE EXPERIENCE OF YEARS"