There are 3 green, 4 orange and 5 white color bulbs in a bag. If a bulb is picked at random, what is the probability of having either a green or a white bulb?

There are some coins and rings of either gold or silver in a box. 60% of the objects are coins, 40% of the rings are of gold and 30% of the coins are silver. What is the percentage of gold articles?

From a pack of 52 cards, two cards are drawn together at random. What is the probability of both the cards being kings?

In how many different ways can the letters of the word 'NATIONAL' be arranged?

Ten different letters of alphabet are given, words with 5 letters are formed from these given letters. Then, how many such words can be formed which have at least one letter repeated ? 

A bag contains 2 red, 3 green and 2 blue balls. Two balls are drawn at random. What is the probability that none of the balls drawn is blue?

In a bag there are 4 white, 4 red and 2 green boxes. Two boxes are drawn at random. What is the probability that at least one boxes is of red colour?

What is the probability of forming word from the letters of word “IMPEACH” such that all vowels come together?