Question

When playing bingo, 50 balls are placed in a bin and balls are selected at random. Each ball is marked with a letter and number as indicated in the chart below. For example, there are balls marked B1, B2, up to B10; I11, I12, up to I20; and so on. Assume one bingo ball is selected at random.

Answer 1

Given :

Total number of balls = 50

Required: odds against it being G39

This implies we are to solve for the

`\frac{probability\text{ }o\text{f not picking a ball labelled G39}}{probability\text{ of picking a ball labelled G39}}`

Probability of not picking a ball labelled G39

`\begin{gathered} P(not\text{ G39) = 1 - P(G39)} \\ =\text{ 1 - }(1)/(50) \\ =(49)/(50) \end{gathered}`

Probability of picking a ball labelled G39

`P(G39)\text{ = }(1)/(50)`

Odds against picking a ball labelled G39

`\begin{gathered} =(49)/(50)\text{ : }(1)/(50) \\ =\text{ 0.98 : 0.02} \\ =49\text{ : 1} \end{gathered}`