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The tree diagram below illustrates the possible outcomes of two tosses of a balanced coin

The tree diagram below illustrates the possible outcomes of two tosses of a balanced-example-1
User Ell Neal
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1 Answer

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We are asked to find the probability that a head comes up on at least one of the coin tosses. This means that it either comes up on the first toss or on the second. We will therfore add the probability of these two events as we are looking for the probability of either.

Probability a heads on the first toss = 0.5 as there are only two possible equally weighted outcomes.

Probability a heads on the second toss = probability of tails first toss*probability of heads on the second toss.

This is because when moving from a node to the branches of that node on a tree diagram we multiply the probabilities.

= 0.5*0.5 = 0.25

The total probability is then equal to 0.25+0.5 = 0.75 (3/4)

Correct option is option number one.

User Himerzi
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