It is known that a box of 600 electric bulbs contains 12 defective bulbs. One bulb is taken out at random from this box. What is the probability that it is a non-defective bulb ?

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

(i) 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? (ii) Suppose the bulb drawn in (i) is not defective and is not replaced. Now one bulb is drawn at random from the rest. Whal is the probability that this bulb is not defective ?

A box contains 12 balls out of which x are black. If one ball is drawn at random from the box, what is the probability that it will be a black ball ?

A box contains 3 blue, 2 white, and 5 red marbles. If a marble is drawn at random from the box, what is die probability that it will be blue?

A lot of 20 bulbs contain 4 defective ones. Suppose the bulb drawn in (i) is not defective and is not replaced. Now one bulb is drawn at random from the rest. What is the probability that this bulb is not defective?

12 defective pens are accidentally mixed up with 132 good ones. It is not possible to just look at a pen and tell whether or not it is defective. One pen is taken out at random from this lot. Determine the probability that the pen taken out is a good one.

A box contains 3 blue, 2 white and 4 red Marbles. If a marble is drawn at random from the box then what is the probability that it will be : Blue ?

A box contains 3 blue, 2 white, and 6 red marbles. If a marble is drawn at random from the box, what is die probability that it will be red?