A drawer contains 50 bolts and 150 nuts. Half bolts and half of the nuts are rusted. If one item is chosen at random what is the probability that it is rusted or is a bolt.

A bag contains 100 bolts and 300 nuts, 50% of each have been rusted. One item is chosen at random. Find the probability that chosen item is rusted or a bolt.

A box contains 100 bolts and 50 nuts. It is given that 50% bolts and 50% nuts are rusted. Two objects are selected from the box at random. Find the probability that both are bolts or both are rusted.

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

A bag contains 5 red, 8 black and 7 white balls. One ball is chosen at random. What is the probability that the chosen ball is back?

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 ?

According to a meteorological report for 300 consecutive days in a year , its weather forecasts were correct 180 times . Out of these days , one day is chosen at random . What is the probability that the weather forecast was not correct on that day ?

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?

On one page of a telephone directory, there were 200 telephone numbers. The frequency distribution of their unit place digit (for example, in the number 25828573, the unit place digit is 3) is given in Table 15.7 : Without looking at the page, the pencil is placed on one of these numbers, i.e., the number is chosen at random. What is the probability that the digit in its unit place is 6?

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?