A lot of$20$ bulbs contain $4$ defective ones. One bulb is drawn at random from the lot. What is the probability that this bulb is defective $?$
 

A lot of $20$ bulbs contain $4$ defective ones. One bulb is drawn at random from the lot. Suppose the bulb drawn is not defective and not replaced. Now, bulb is drawn at random from the rest. What is the probability that this bulb is not defective?

A bag contains lemon-flavoured candies only. Hema takes out one candy without looking into the bag. What is the probability that she takes out an orange-flavoured candy $?$

A bag contains lemon-flavoured candies only. Hema takes out one candy without looking into the bag. What is the probability that she takes out a lemon-flavoured candy $?$

One card is drawn from a well-shuffled deck of $52$ cards. Find the probability of drawing an ace.

One card is drawn from a well-shuffled deck of$52$ cards. Find the probability of drawing a $\text{'}4\text{'}$ of spades.

One card is drawn from a well-shuffled deck of $52$cards. Find the probability of drawing a $\text{'}9\text{'}$ of a black suit.