## If Jesse flips a coin seven times in a row, what is the probability that the result will be heads at least five times?

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### If Jesse flips a coin seven times in a row, what is the probability that the result will be heads at least five times?

by AAPL » Sat Aug 05, 2023 7:33 am

00:00

A

B

C

D

E

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Veritas Prep

If Jesse flips a coin seven times in a row, what is the probability that the result will be heads at least five times?

A. $$21/128$$
B. $$29/128$$
C. $$35/128$$
D. $$1/16$$
E. $$1/4$$

OA B

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### Re: If Jesse flips a coin seven times in a row, what is the probability that the result will be heads at least five time

by swerve » Sun Aug 13, 2023 9:19 am
AAPL wrote:
Sat Aug 05, 2023 7:33 am
Veritas Prep

If Jesse flips a coin seven times in a row, what is the probability that the result will be heads at least five times?

A. $$21/128$$
B. $$29/128$$
C. $$35/128$$
D. $$1/16$$
E. $$1/4$$

OA B
Probability to get at least $$5$$ heads in $$7$$ flips.

The total outcome of flip is $$= 2^7 = 128$$
For any Coins problem write the ask in the shown format.

$$HHHHHTT$$
$$HHHHHHT$$
$$HHHHHHH$$

Once you have written in the above mentioned format the answer is pretty straight.

$$HHHHHTT = \dfrac{7!}{5! \cdot 2!} = 21$$

$$HHHHHHT = \dfrac{7!}{6!} = 7$$

$$HHHHHHH = \dfrac{7!}{7!} = 1$$

Sum $$= 21+7+1 = 29/128$$

Therefore, B

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