Math Problem Statement

In a class of 19 students, 6 are female and 10 have an A in the class. There are 7 students who are male and do not have an A in the class. What is the probability that a student who has an A is a male?

Solution

To solve this problem, we can use the principles of probability. Here's a step-by-step breakdown:

Step 1: Define the variables

  • Total students (T): 19
  • Female students (F): 6
  • Students with an A (A): 10
  • Male students without an A (M' ∩ A'): 7

Step 2: Determine the number of male students

Since the total number of students is 19 and there are 6 female students, the number of male students MM is: M=TF=196=13M = T - F = 19 - 6 = 13

Step 3: Determine the number of male students with an A

We know that the number of male students who do not have an A is 7. Since there are 13 male students in total, the number of male students with an A MAM \cap A is: MA=M(MA)=137=6M \cap A = M - (M' \cap A') = 13 - 7 = 6

Step 4: Calculate the probability

We need to find the probability that a student who has an A is a male. This can be represented as: P(MA)=P(MA)P(A)P(M \mid A) = \frac{P(M \cap A)}{P(A)} Where:

  • P(MA)P(M \cap A) is the number of male students with an A, which is 6.
  • P(A)P(A) is the total number of students with an A, which is 10.

Substituting the values, we get: P(MA)=610=35=0.6P(M \mid A) = \frac{6}{10} = \frac{3}{5} = 0.6

Final Answer

The probability that a student who has an A is a male is 0.6\boxed{0.6} or 60%.

Would you like more details or have any questions?


Here are some related questions:

  1. What is the probability that a student selected at random is a female with an A?
  2. What is the probability that a student who is male does not have an A?
  3. How many students have neither an A nor are male?
  4. What is the probability that a student selected at random is male?
  5. How does the addition of one more female student with an A affect the probability?

Tip: When dealing with conditional probabilities, clearly identify the events and use the conditional probability formula P(BA)=P(AB)P(A)P(B \mid A) = \frac{P(A \cap B)}{P(A)}.

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Math Problem Analysis

Mathematical Concepts

Probability
Conditional Probability

Formulas

P(B|A) = P(A ∩ B) / P(A)

Theorems

Conditional Probability Theorem

Suitable Grade Level

Grades 9-10