The probability of scoring $100$ marks in a question paper of $100$ marks is ................

There are $5$ white,$7$ red,$4$ black,and $2$ blue identical balls in a box. One ball is selected at random from the box. Find the probability that the selected ball is either white or blue.

$A$ card is drawn at random from a well-shuffled pack of $52$ cards. Find the probability that the card drawn is a face card.

$A$ card is selected from a deck of $52$ cards. The probability of its being a red face card is

$A$ bag contains slips numbered from $1$ to $100$. If Fatima chooses a slip at random from the bag,it will either be an odd number or an even number. Since this situation has only two possible outcomes,the probability of each is $\frac{1}{2}$. Justify.

$A$ lot consists of $48$ mobile phones of which $42$ are good,$3$ have only minor defects,and $3$ have major defects. Varnika will buy a phone if it is good,but the trader will only buy a mobile if it has no major defect. One phone is selected at random from the lot. What is the probability that it is
$(i)$ acceptable to Varnika?
$(ii)$ acceptable to the trader?