Probability of Getting the Main Doorprize

Apr 2018
159
37
Sukoharjo
There's an event which is joined by 240 members. The Event Organizer prepares 30 doorprize with one of them being the main ones. If Mr. Aziz's family has 15 tickets, the probability that Mr. Aziz gets the main doorprize is ....
A. 1/16
B. 1/8
C. 1/4
D. 1/2

I thought the answer was 15/240 (the probability of Mr. Aziz's family getting the doorprize) times 1/30 (the main one among the doorprize) and it results in 1/480, but it's not in the options. Is the book wrong or am I the one who miscalculated?
 

Debsta

MHF Helper
Oct 2009
1,313
599
Brisbane
Forget there are 30 door prizes. The only only one of interest in the problem is the 1 main prize. The Aziz family has 15 of the 240 tickets, so the probability that they win the main prize is ....? Hint: the correct answer is one of the options given.
 
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Apr 2018
159
37
Sukoharjo
Damn, of course! 1 ticket only corresponds to one door prize, so the probability is as simple as 15/240 = 1/16. Silly me.
 
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