Find the probability of the following event: 

The sum of two odd numbers is even.

Find the probability of the following event: 

Drawing a red card from a well-shuffled deck of playing cards.

Find the probability of a following event:

Getting an odd number when a die is thrown once.

A box contains $3$ red balls, $7$ black balls and $5$ green balls. One ball is drawn from the box at random. Find the probability of drawing a green ball.

A box contains $3$ red balls, $7$ black balls and $5$ green balls. One ball is drawn from the box at random. Find the probability of drawing a black or red ball.

A box contains $3$ red balls, $7$ black balls and $5$ green balls. One ball is drawn from the box at random. Find the probability of drawing a ball that is not black.

If one letter is chosen at random from the word "MATHEMATICS", find the probability of getting M.

If one letter is chosen at random from the word "MATHEMATICS", find the probability of getting A.

If one letter is chosen at random from the word "MATHEMATICS", find the probability of getting S.