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?
(i) \(\dfrac{5}{17}\)
(ii) \(\dfrac{8}{17}\)
(iii) 13/17
Total number of marbles = 5 + 8 + 4 = 17. So P(red) = \(\dfrac{5}{17}\) and P(white) = \(\dfrac{8}{17}\). The event “not green” means the marble is either red or white, so the favourable marbles are 5 + 8 = 13 and P(not green) = 13/17.