Can you replace the question mark with the correct number?

Krish is 45 years old and his mother Crishtina is 73 years old.

Can you find out how many years ago, his mother was three times his age?

Can you find the hidden animal in the picture below?

Replace the question mark with the correct number in the below-given picture?

A bag contains 64 balls of eight different colours. There are eight of each colour (including red). What is the least number you would have to pick, without looking, to be sure of selecting 3 red balls?

This is a picture puzzle. You have to guess the name of the movie that can be related to the picture.

The ages of a father and son add up to 66.
The father's age is the son's age reversed.
How old could they be?
(3 possible solutions).

What's the next in the series?

H, Be, F, S, Mn, Kr, In, Gd, Tl, ?

What is 3/7 chicken, 2/3 cat and 2/4 goat?

13 decks of cards have been mixed. What is the minimum number of cards that must be taken out from the above-mixed cards to guarantee at least one 'four of a kind?