$2$ dice are thrown. Find the probability of getting an odd number as the sum.

$A$ bag contains $8$ red and $7$ black balls. Two balls are drawn at random. The probability that both the balls are of the same colour is

An $URN$ contains $6$ blue,$4$ red,$3$ green and $2$ yellow marbles. If four marbles are picked at random,what is the probability that one is yellow,two are red and one is blue?

$A$ box contains $3$ white and $2$ red balls. $A$ ball is drawn and another ball is drawn without replacing the first ball. Then,the probability of the second ball being red is:

$A$ drawer contains $50$ bolts and $150$ nuts. Half of the bolts and half of the nuts are rusted. If $1$ item is chosen at random,what is the probability that it is rusted or is a bolt?

One bag contains $5$ white and $3$ black balls and a second bag contains $2$ white and $4$ black balls. One ball is drawn from the first bag and placed unseen in the second bag. What is the probability that a ball now drawn from the second bag is black?