Question

Rosa is attending an event where prizes are being given away. The probability of winning a T‐shirt is 0.89 and the probability of winning a $20 gift certificate is 0.05. Which statement correctly describes the chances of Rosa winning a T‐shirt or a $20 gift certificate? It is very likely that Rosa wins both prizes.

Answer 1

It is very likely that Rosa wins both prizes.

Explanation:

The probability of winning a T‐shirt is 0.89 and the probability of winning a $20 gift certificate is 0.05. Which statement correctly describes the chances of Rosa winning a T‐shirt or a $20 gift certificate?

We have these three possibe outcomes.

Win t-shirt(0.89 probability) and lose the gift certiciate(1 - 0.05 = 0.95 probability)

Lose t-shirt(0.11 probability) and win the gift certiciate(0.05 probability).

Win both.

So

`p = 0.89*0.95 + 0.11*0.05 + 0.89*0.05 = 0.8955`

0.8955 = 89.55% probability of Rosa winning a T‐shirt or a $20 gift certificate, which is considered a very likely probability. So the answer is:

It is very likely that Rosa wins both prizes.