What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

I am first found in caves, now prolific online; I am a depiction, a drawing, a symbol, or sign. I will convey whichever mood you could wish; or for that matter, a fist, flask, or fish. What am I?

How many Watermelons are there in the below picture?

A number can be multiplied by multiple of nine
i.e 9 18 27 36 45 ...

and the resulting number consist of only one digit.

Can you identify the number ?

Solve this riddle by finding the odd one out from the rest.

Can you identify the famous TV character from the rebus below?

You need to arrange three 7 and mathematical symbols to form number 1?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

Replace the question mark with the correct number below.

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?