In a lottery there are $10$ prizes and $25$ blanks. What is the probability of getting a prize? 

A bag contains $5$ black, $7$ red and $3$ white balls. A ball is drawn from the bag at random. Find the probability that the ball drawn is red.

A bag contains $5$ black, $7$ red and $3$ white balls. A ball is drawn from the bag at random. Find the probability that the ball drawn is black or white.

A bag contains $5$ black, $7$ red and $3$ white balls. A ball is drawn from the bag at random. Find the probability that the ball drawn is not black 

A bag contains $4$ red, $5$ black and $6$ white balls. A ball is drawn from the bag at random. If the probability that the ball drawn is white is $\frac{k}{5}$, find $k$.

A bag contains $4$ red, $5$ black and $6$ white balls. A ball is drawn from the bag at random. Find the probability that the ball drawn is red.

A bag contains $4$ red, $5$ black and $6$ white balls. A ball is drawn from the bag at random. Find the probability (in the simplest form of fraction) of not drawing a black ball.

A bag contains $4$ red, $5$ black and $6$ white balls. A ball is drawn from the bag at random. Find the probability that the ball drawn is red or white.