There are two red, two blue, two white, and certain number (greater than 0) of green socks in a drawer. If two socks are taken at random from the drawer without replacement, the probability that they are of the same color is `1//5`, then the number of green socks are _______.

A box contains 7 white and 5 black balls two are drawn at random find the probability that they are not of the same colour when the balls are drawn at a time

If two numbers are selected at random from the numbers 1,2,3,4 determine the probability that their sum is odd when they are selected together.

An urn contains 4 balls. Two balls are drawn at random from the urn (without replacement) and are found to be white. What is the probability that all the four balls in the urn are white ?

An urn contains 10 black and 5 white balls. Two balls are drawn from the urn one after the other without replacement. What is the probability that both balls are black?

An urn contains nine balls of which three are red, four are blue and two are green. Three balls are drawn at random without replacement from the urn. The probability that the three balls have different colour is

Two unbiased dice are thrown. Find the probability that the total of the numbers on the dice is greater than 10.

An urn contains 10 black and 5 white balls. Two balls are drawn from the urn one after the other without replacement. What is the probability that both drawn balls are black?

Two cards are drawn at random and without replacement from a pack of 52 playing cards. Find the probability that both the cards are black.

A bag contains 5 red caps and 4 blue caps. The probability that two drawn caps are on same colour is

A drawer contains a mixture of red socks and blue socks, at most 17 in all. It so happens that when two socks are selected randomly without replacement, there is a probability of exactly 1/2 that both are red or blue. The largest possible number of red socks in the drawer that is consistent with this data is _______.