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# edexcel S1 probablilty question watch

1. I'm having trouble with parts c) and d) of the following question!

Paul and Gill decide to play a board game. The probability that Paul wins the game is 0.25 and the probability that Gill wins is 0.3. They play 3 games. Results of successive games are independent. Find the probability that:

a)Paul wins all three games.
0.25 x 0.25 x 0.25 = 0.00156 (correct answer)
b)All games are drawn.
0.45 x 0.45 x 0.45 = 0.0911 (correct answer)
c)Gill wins two and paul wins one.
0.3 x 0.3 x 0.25 = 0.0225 (the answer is three times this - 0.0675, why do you multiply by three?
d)Each player wins one and the other game is drawn
0.25 x 0.3 x 0.45 = 0.03375 (the answer is six times this - 0.2025, why do you multiply by six?

The answers probably obvious and am probably gonna kick myself but any help will be appreciated cheers!
2. (Original post by tdx)
I'm having trouble with parts c) and d) of the following question!

Paul and Gill decide to play a board game. The probability that Paul wins the game is 0.25 and the probability that Gill wins is 0.3. They play 3 games. Results of successive games are independent. Find the probability that:

a)Paul wins all three games.
0.25 x 0.25 x 0.25 = 0.00156 (correct answer)
b)All games are drawn.
0.45 x 0.45 x 0.45 = 0.0911 (correct answer)
c)Gill wins two and paul wins one.
0.3 x 0.3 x 0.25 = 0.0225 (the answer is three times this - 0.0675, why do you multiply by three?
d)Each player wins one and the other game is drawn
0.25 x 0.3 x 0.45 = 0.03375 (the answer is six times this - 0.2025, why do you multiply by six?

The answers probably obvious and am probably gonna kick myself but any help will be appreciated cheers!
Think of the number of ways in which these events can occur
3. You haven't counted all the possible combinations.
4. (Original post by Indeterminate)
Think of the number of ways in which these events can occur

(Original post by SherlockHolmes)
You haven't counted all the possible combinations.
ahhhhh thank you! .. as predicted seems obvious now haha

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