Question

coin $a$ is flipped three times and coin $b$ is flipped four times. what is the probability that the number of heads obtained from flipping the two fair coins is the same?

Answer 1

The probability that the number of heads obtained from flipping the two fair coins is the same is 35/128.

Probability:

Probability means the fraction of favorable outcome and the total number of outcomes.

So it can be written as,

Probability = Favorable outcomes / Total outcomes

Given,

The coin a is flipped three times and coin b is flipped four times.

Here we need to find the probability that the number of heads obtained from flipping the two fair coins is the same.

We know that,

There are 4 ways that the same number of heads will be obtained;

0, 1, 2, or 3 heads.

The probability of both getting 0 heads is

$\left(\frac12\right)^3{3\choose0}\left(\frac12\right)^4{4\choose0}=\frac1{128}$

Probability of getting 1 head,

$\left(\frac12\right)^3{3\choose1}\left(\frac12\right)^4{4\choose1}=\frac{12}{128}$

Probability of getting 2 heads is,

$\left(\frac12\right)^3{3\choose2}\left(\frac12\right)^4{4\choose2}=\frac{18}{128}$

And the probability of getting 3 heads is,

$\left(\frac12\right)^3{3\choose3}\left(\frac12\right)^4{4\choose3}=\frac{4}{128}$

Therefore, the probability that the number of heads obtained from flipping the two fair coins is the same is,

=> (1/128) + (12/128) + (18/128) + (4/128)

=> 35/128.

To know more about probability here

brainly.com/question/14210034

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