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?

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

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?

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?

A basket consists of five blue balls, four green balls, two red balls and three yellow balls. Three balls are drawn at random. What is the probability that at least one blue ball is drawn?

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

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?

A bag contains 30 balls, numbered 1 to 30. Two balls are drawn at random. What is the probability that the balls drawn contain a number which is multiple of 4 or 6 but not a multiple of both?