0.308
Step-by-step explanation
The probability of an event is the number of favorable outcomes divided by the total number of outcomes possible,so

so
Step 1
favourable outcome is the result that is desired, so as the result is a that Raphael purchase the ticket
a) Let

and , the total outcome is the total ticket,so

b) now, replace in the formula:

therefore,the answer is 0.308
I hope this helps you