The experiment in which all possible results are known in advance but none of them can be predicted with certainty and there is equal possibility for each result is known as a ‘Random experiment’.
For example, Tossing a coin, throwing a die, picking a card from a set of cards bearing numbers from 1 to 50, picking a card from a pack of well shuffled playing cards, etc.
Result of a random experiment is known as an ‘Outcome’.
- In a random experiment of tossing a coin - there are only two outcomes.Head (H) or Tail (T)
- In a random experiment of throwing a die, there are 6 outcomes, according to the number of dots on the six faces of the die. 1 or 2 or 3 or 4 or 5 or 6.
- In a random experiment of picking a card bearing numbers from 1 to 50, there are 50 outcomes.
- A card is drawn randomly from a pack of well shuffled playing cards. There are 52 cards in a pack as shown below.
In a pack of playing cards there are 4 sets, namely heart, diamond, club and spade. In each set there are 13 cards as King, Queen, Jack, 10, 9, 8, 7, 6, 5, 4, 3, 2 and Ace.
King, Queen and Jack are known as face cards. In each pack of cards there are 4 cards of king, 4 cards of Queen and 4 cards of Jack. Thus total face cards are 12.
A bag contains in all 50 balls. Some of them are white, some are blue and some are red. The number of white balls is 11 times the number of blue balls. The number of red balls is less than the number of white balls. Also, the number of red balls is more than the number of blue balls. If one of the balls is selected at random from the bag, what is the probability that it is red ?