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Re: When a coin is flipped, the probability of getting heads is [#permalink]
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In Magoosh, it,s a hard question not medium.
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Re: When a coin is flipped, the probability of getting heads is [#permalink]
can you please elaborate this calculating each part? Because, there may be some questions in GRE which needs calculations.
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Re: When a coin is flipped, the probability of getting heads is [#permalink]
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For, the probability of getting two heads exactly, when coin is tossed 5 times,

the no. of favorable outcome= arrangement of 2 H and 3 T(HHTTT)= 5!/(2!*3!)=10
the total no of outcomes for tossing coin 5 times =2^5=32
therefore required probablity=10/32

If we follow same steps for getting exactly 3 heads the result will be same.... am I incorrect????
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Re: When a coin is flipped, the probability of getting heads is [#permalink]
someone please follow up with subasyahoo. i'd like to to see the calculations as well - for quantity A and quantity B. This will be very helpful.
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Re: When a coin is flipped, the probability of getting heads is [#permalink]
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Given that When a coin is flipped, the probability of getting heads is 0.5, and the probability of getting tails is 0.5 A coin is flipped 5 times.

Coin is tossed 5 times => Total number of cases = \(2^5\) = 32

Quantity A: Probability of getting exactly 2 Heads

We need to get 2 heads out of 5 tosses.

We have 5 places to fill _ _ _ _ _ and we need to put 2 heads in those five places, which we can do in 5C2 ways

=> \(\frac{5!}{2!*(5-2)!}\) = \(\frac{5*4*3!}{2!*3!}\) = 10 ways

=> P(2H) = \(\frac{10}{32}\) = \(\frac{5}{16}\)

Quantity B: Probability of getting exactly 3 Heads

We need to get 3 heads out of 5 tosses.

We have 5 places to fill _ _ _ _ _ and we need to put 3 heads in those five places, which we can do in 5C3 ways

=> \(\frac{5!}{3!*(5-3)!}\) = \(\frac{5*4*3!}{3!*2!}\) = 10 ways

=> P(3H) = \(\frac{10}{32}\) = \(\frac{5}{16}\)

Clearly, Quantity A = Quantity B = \(\frac{5}{16}\)

So, Answer will be C
Hope it helps!

Watch the following video to learn How to Solve Probability with Coin Toss Problems

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