It is known that 10% of certain articles manufactured are defective . What is the probability that in a random sample of 12 such articles 9 are defective?

A box contains 10 bulbs, of which just three,are defective. If a random sample of five bulbs is drawn, find the probabilities that the sample contains: i) exactly one defective bulb (ii)exactly two defective bulbs (iii) no defective bulbs.

A word consists of 9 letters: 5 consonants and 4 vowels. Three letters are chosen at random. Find the probability that the selection of the three letters contains more than one vowel.

A factory has two machines A and B. past record shows that machine A produced 60% of the items of output and the machine B produced 40% of the items. Future 2% of the items produced by machine A and 1% produced by machine B were defective. All the items are put into one stockpile and then one item is choosen at random from this and is found to be defective. what is the probability that it was produced by machine B ?

Ten eggs are drawn successively with replacement from a lot containing 10% defective eggs. Find the probability that there is at least one defective egg.

In a factory which manufacture bulbs,machine X, Y and Z manufactures respectively 25%, 35% and 40% of the bulbs. Of the output 1%, 2% and 3% are respectively defective bulbs. A bulb is drawn at random and found to be defective. What is the probability that it is manufactured by machine Y ?

The probability that a bulb produced by a factory will fuse after 150 days of use is 0.05. Find the probability that out of 5 such bulbs. not more than one

In a hurdle race, a player has to croșs 10 hurdles. The probability that he will clear hurdle is 5/6 . What is the probability that he will knock down fewer than 2 hurdles?

A box contains 400 electronic toy'cars.Among them,12 are defective. One toy is taken out at random.What is the probability tha It is a non-defective toy.