12 defective pens are accidentally mixed 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.

14 defective bulbs are accidentally mixed with 98 good ones. It is not possible to just look at the bulb and tell whether it is defective or not. One bulb is taken out at random from this lot. Determine the probability that the bulb taken out is a good one.

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 ?

It is known that a box of 200 electric bulbs contains 16 defective pieces. One bulb is taken out at random. What is the probability that it is (i) defective (ii) not defective ?

A bag contains 3 red balls, 5 white balls and 8 blue balls. One ball is taken out of the baf at random. fine the probability that the ball taken out is (a) a red ball, (b) not a white ball.

A box contains 5 red marbles, 8 white marbles and 4 green marbles . One marble is taken out of the box at random. What is the probillity that the marble taken out will be red ?

A box contains 5 red marbles, 8 white marbles and 4 green marbles . One marble is taken out of the box at random. What is the probillity that the marble taken out will be not green ?

A box contains 5 red marbles, 8 white marbles and 4 green marbles . One marble is taken out of the box at random. What is the probillity that the marble taken out will be white ?

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

A box contains 144 pens of which 20 are defective and the others are good. A person will buy a pen if it is good and will not buy if it is defective. The shopkeeper draws one pen from the box at random and gives it to the person. What is the probability that the person (a) will buy it? (b) will not buy it?

A box contains 5 red marbles, 8 white marbles and 4 green marbles. One marble is taken out of the box at random . What is the probability that the marble taken out will be (i) red ? (ii) white ? (iii) not green ?