We have two coins, a and b. for each toss of coin a, we obtain heads with probability 1/2 ; for each toss of coin b, we obtain heads with probability 1/3 . all tosses of the same coin are independent. we toss coin a until heads is obtained for the first time. we then toss coin b until heads is obtained for the first time with coin b. the expected value of the total number of tosses is:

The expected value is 5.

Step-by-step explanation:

As we can see, X=Y+Z. Then, by the linearity of the expected value operator, we have that

Observe that Y and Z have countable sets of outcomes (1,2,3,....) then,

,

,

Then:

Observe that, by the geometric series formula:

Therefore

Finally, E(X)=E(Y)+E(Z)=2+3=5.

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times both sides by 2, times () by 8, add alile terms, move terms, add alike and caculate divide both sides by 3

the option best identifies the textual evidence that supports this conclusion is c.) when an argument is over, how many weighty reasons does a man recollect which his heat and violence made him utterly forget? in order to recognize textual evidence is to identify the topic sentence where the author states the main idea. textual evidence is what supports the topic sentence or main idea of a passage.