Harpreet tosses two different coins simultaneously (say,one is of $Rs. 1$ and other of $Rs. 2$). What is the probability that she gets at least one head?

$A$ piggy bank contains $100$ $50\, p$ coins,$50$ $Rs.\, 1$ coins,$20$ $Rs.\, 2$ coins,and $10$ $Rs.\, 5$ coins. If it is equally likely that one of the coins will fall out when the bank is turned upside down,what is the probability that the coin:
$(i)$ will be a $50\, p$ coin?
$(ii)$ will not be a $Rs.\, 5$ coin?

Suppose we throw a die once. $(i)$ What is the probability of getting a number greater than $4$? $(ii)$ What is the probability of getting a number less than or equal to $4$?

$A$ box contains $3$ blue,$2$ white,and $4$ red marbles. If a marble is drawn at random from the box,what is the probability that it will be
$(i)$ white?
$(ii)$ blue?
$(iii)$ red?

$A$ lot consists of $144$ ball pens of which $20$ are defective and the others are good. Nuri will buy a pen if it is good,but will not buy if it is defective. The shopkeeper draws one pen at random and gives it to her. What is the probability that
$(i)$ She will buy it?
$(ii)$ She will not buy it?

Complete the following statements:
$(i)$ The sum of the probabilities of all the elementary events of an experiment is .......
$(ii)$ The probability of an event is greater than or equal to ....... and less than or equal to .......