A bag contains $3$ red, $4$ white and $5$ blue balls. All balls are different. Two balls are drawn at random. The probability that they are of different colour is
$\frac{{47}}{{66}}$
$\frac{{10}}{{33}}$
$\frac{5}{{22}}$
None of these
Three mangoes and three apples are in a box. If two fruits are chosen at random, the probability that one is a mango and the other is an apple is
A bag contains $5$ brown and $4$ white socks. A man pulls out two socks. The probability that these are of the same colour is
Two numbers are selected at random from $1, 2, 3 ......100$ and are multiplied, then the probability correct to two places of decimals that the product thus obtained is divisible by $3$, is
A box contains $25$ tickets numbered $1, 2, ....... 25$. If two tickets are drawn at random then the probability that the product of their numbers is even, is
Two numbers $a$ and $b$ are chosen at random from the set of first $30$ natural numbers. The probability that ${a^2} - {b^2}$ is divisible by $3$ is