Question 1 Report
Three red balls, five green balls, and a number of blue balls are put together in a sack. One ball is picked at random from the sack. If the probability of picking a red ball is \(\frac{1}{6}\) find;
(a) The number of blue balls in the sack
(b) the probability of picking a green ball
3 red, 5 green, \(b\) blue. Total \(=8+b\). \(P(\text{red})=\dfrac{3}{8+b}=\dfrac{1}{6}\).
(a) \(3\times 6 = 8+b \Rightarrow 18=8+b \Rightarrow b=\mathbf{10}\) blue balls.
Total balls \(=3+5+10=18\).
(b) \(P(\text{green})=\dfrac{5}{18}\).
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