In a class of $60$ students, $40$ opted for $NCC,\,30$ opted for $NSS$ and $20$ opted for both $NCC$ and $NSS.$ If one of these students is selected at random, then the probability that the student selected has opted neither for $NCC$ nor for $NSS$ is

A fair coin is tossed four times, and a person win $\mathrm {Rs.}$ $1$ for each head and lose  $\mathrm {Rs.}$ $1.50$ for each tail that turns up. From the sample space calculate how many different amounts of money you can have after four tosses and the probability of having each of these amounts.

A die is thrown, find the probability of following events: A number less than or equal to one will appear,

From the word `$POSSESSIVE$', a letter is chosen at random. The probability of it to be $S$ is

Two dice are thrown. The events $A, B$ and $C$ are as follows:

$A:$ getting an even number on the first die.

$B:$ getting an odd number on the first die.

$C:$ getting the sum of the numbers on the dice $\leq 5$

Describe the events $B$ or $C$

A die is thrown, find the probability of following events: A number less than $6$ will appear,