Question

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?

Answer 1

Here, total number of marbles `n(S)= 5+8+4 = 17`
Number of red marbles, `n(E_r) = 5`
Number of white marbles, `n(E_w) = 8`
Number of green marbles, `n(E_g) = 4`
So, probablity marble taken is red, `P(E_r) =(n(E_r))/(n(S)) = 5/17`
Probablity marble taken is white, `P(E_w) = (n(E_r))/(n(S))=8/17`
Probablity marble taken is green, `P(E_g) = (n(E_g))/(n(S))=4/17`
Probablity marble taken is not green, `= 1 - P(E_g) = 1-4/17=13/17`