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At a local hospital, a quarter of the babies are born with no hair on their head, half the babies are born with a little hair, and the rest are born with a lot of hair. If I choose two babies at random, what is the probability that I will choose one baby with no hair and another with a little hair?

A. 1/8
B. 1/4
C. 3/8
D. 1/2

User Ppasler
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1 Answer

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Final answer:

When calculating the combined probability of choosing one baby with no hair and another with a little hair from the local hospital, the rules of probability and combination of events are applied, yielding a 1/4 chance. This is the sum of the probabilities of the two possible selection orders, resulting in option B. 1/4 as the correct answer.

Step-by-step explanation:

To find the probability that one of the two randomly chosen babies has no hair and the other has a little hair, we need to consider the probabilities of each event and use the rules of probability for combined events.

A quarter of the babies are born with no hair, which is a probability of ¼, and half the babies are born with a little hair, which is a probability of ½. The rest of the babies, which would be ¼, are born with a lot of hair, but this is irrelevant to the question.

In this scenario, since there are two distinct events — choosing a baby with no hair and choosing a baby with a little hair — we use the product rule of probability where we multiply the probability of each independent event. However, since the order does not matter (it could be first no hair and then a little hair, or first a little hair and then no hair), we must consider both possibilities.

  • Probability of first choosing a baby with no hair and then one with a little hair: (¼) × (½).
  • Probability of first choosing a baby with a little hair and then one with no hair: (½) × (¼).

Since these are two separate ways that the desired outcome can occur, we use the sum rule of probability to combine them: (¼ × ½) + (½ × ¼).

Calculating this gives: (1/4 × 1/2) + (1/2 × 1/4) = 1/8 + 1/8 = 2/8 or simplified to 1/4.

The correct answer is B. 1/4, which is the probability of choosing one baby with no hair and another with a little hair from the local hospital.

User Xtiger
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