Probability

At a charity fundraiser there have been a total of 342 raffle tickets already sold. If a person then purchases two tickets rather than one, how much more likely are they to win? A) 2.10. B) 1.99. C) 0.50.

Answer–>© 0.5 purchasing ticket is independent of each other… x -> Probability of wining by purchasing only 1 ticket will be 1/342 = 1/342 y -> Probability of wining by purchasing 2 tickets will be 2/342 = 2/342 The difference is -> 0.5

I would guess B. If they purchase the first ticket their chances are 1/342. If they buy the second ticket there are now 343 tickets sold, so your chances are 2/343. (1/342)/(2/343)= 1.9942.

The answer is B If you purchase one ticket, the probability of your ticket being drawn is 1/343 or 0.00292. If you purchase two tickets, your probability becomes 2/344 or 0.00581, so you are 0.00581 / 0.00292 = 1.99 times more likely to win.

Again with the wording on the question. I got B as well, but it is sometimes difficult to figure out what they are asking. Probably more so for ESL students.