$A$ jar contains $3$ red marbles,$7$ green marbles and $10$ white marbles. If a marble is drawn from the jar at random,what is the probability that this marble is white?

$1$ bag contains $4$ white and $2$ black balls. Another bag contains $3$ white and $5$ black balls. If $1$ ball is drawn from each bag,find the probability that $1$ ball is white and $1$ ball is black.

$A$ bag contains $3$ red,$7$ white,and $4$ black balls. If three balls are drawn from the bag,the probability that all of them are of the same color is:

$A$ bag contains $3$ red and $7$ black balls. Two balls are taken out at random,without replacement. If the first ball taken out is red,what is the probability that the second ball taken out is also red?

Two cards are drawn together from a pack of $52$ cards. The probability that one is a spade and one is a heart,is

An unbiased die is tossed until a number greater than $4$ appears. The probability that an even number of tosses is needed is