Bag/ Box / Piggy bank
Bag/ Box / Piggy bank
Last updated at April 16, 2024 by Teachoo
Ex 14.1, 9 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? Total number of marbles = 5 + 8 + 4 = 17 Number of marbles which are white = 5 P(marble taken out is red) = (ππ’ππππ ππ πππππππ π€βππβ πππ πππ)/(πππ‘ππ ππ’ππππ ππ πππππππ ) = π/ππ Ex 14.1, 9 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 (ii) white? Total number of marbles = 17 Number of marbles which are white = 8 P(marble taken out is white) = (ππ’ππππ ππ πππππππ π€βππβ πππ π€βππ‘π)/(πππ‘ππ ππ’ππππ ππ πππππππ ) = π/ππ Ex 14.1, 9 (Method 1) 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 (iii) not green? P(marble taken out is not green) = P(marble taken out is white) + P(marble taken out is red) = 8/17 + 5/17 = ππ/ππ Ex 14.1, 9 (Method 2) 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 (iii) not green? P(marble taken out is not green) = 1 β P(marble taken out is green) Total number of marbles = 17 Number of marbles which are green = 4 P(marble taken out is green) = (ππ’ππππ ππ πππππππ π€βππβ πππ πππππ)/(πππ‘ππ ππ’ππππ ππ πππππππ ) = π/ππ Now, P(marble taken out is not green) = 1 β P(marble taken out is green) = 1 β π/ππ = (17 β 4)/17 = ππ/ππ