Question

St. Mary's Church is holding a raffle in which 1172 tickets have been sold at a cost of $2.00 each. Three prizes will be awarded: 1 for S500;1 for $250; 1 for $125. If you buy one ticket, then your expected value for this raffle is $ You do not need to include the dollar sign (S) with your answer. Give your answer as numerical value rounded to 2 decimal places. No $ sig?n

Answer 1

- 1.25 ( approx )

Explanation:

Given,

Total tickets = 1172,

In which every ticket costs $ 2, also, three prizes will be awarded 1 for $ 500, 1 for $250 and 1 for $125.

`\because \text{Probability}=\frac{\text{Number of favourable outcomes}}{\text{Total outcomes}}`

Thus, we can make a table that represents the given situation,

Number of tickets 1 1 1 1169

Probability of ticket 1/1172 1/1172 1/1172 1169/1172

Price of ticket $ 500 $ 250 $ 125 - $ 2

( Note : Negative sign shows the loss, i.e. if we could not get any price then we have a loss of $ 2 )

Thus, the expected value of a ticket

`=(1)/(1172)* 500+(1)/(1172)* 250+(1)/(1172)* 125+(1169)/(1172)* -2`

`=(500)/(1172)+(250)/(1172)+(125)/(1172)-(2338)/(1172)`

`=-1.24829351536`

`\approx -1.25`