An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?
Answer (2)
The number of electrons that flow through an electrical device delivering a current of 15.0 A over 30 seconds is approximately 2.81 × 1 0 21 electrons. This is calculated by first finding the total charge and then dividing by the charge of a single electron. Essentially, using Q = I × t and n = e Q gives us the required count of electrons.
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Find the total number of houses with 2 bathrooms: 30.
Find the number of houses with 2 bathrooms and 3 bedrooms: 24.
Calculate the conditional probability: 30 24 = 0.8 .
The probability that a randomly selected house with 2 bathrooms has 3 bedrooms is 0.8 .
Explanation
Understand the problem and provided data We are given a two-way table that shows the number of houses on the market in the Castillos' price range, categorized by the number of bedrooms and bathrooms. The problem asks for the probability that a randomly selected house with 2 bathrooms has 3 bedrooms. This is a conditional probability problem.
Identify the relevant numbers from the table From the table, we can see that the total number of houses with 2 bathrooms is 30. The number of houses with 2 bathrooms and 3 bedrooms is 24.
Calculate the conditional probability To find the conditional probability, we will use the formula: P ( 3 bedrooms ∣2 bathrooms ) = Total number of houses with 2 bathrooms Number of houses with 2 bathrooms and 3 bedrooms Plugging in the values from the table: P ( 3 bedrooms ∣2 bathrooms ) = 30 24 Now, we simplify the fraction: 30 24 = 5 4 = 0.8
State the final answer The probability that a randomly selected house with 2 bathrooms has 3 bedrooms is 0.8.
Examples
This type of probability calculation is useful in real estate to understand the distribution of houses based on features like the number of bedrooms and bathrooms. For example, a real estate agent might want to know the probability that a house with a certain number of bathrooms also has a specific number of bedrooms to better target potential buyers. This can also help in pricing strategies, as certain combinations of features might be more desirable and thus command a higher price. Understanding these probabilities can lead to more informed decisions in buying, selling, and investing in real estate.
