In a group of students, each student is taking a mathematics course or acomputer science course or both. One-fifth of those taking a mathematics course arealso taking a computer science course, and one-seventh of those taking a computerscience course are also taking a mathematics course. What percentage of the studentsare taking a mathematics course

Respuesta :

Answer:

63.64%

Step-by-step explanation:

Let P(M) be the percentage of students enrolled in a mathematics course

Let P(C) be the percentage of students enrolled in a Computer Science (CS) course.

We are told that One-fifth of those taking a mathematics course arealso taking a computer science course.

Thus, we can write that as:

P(M|C) = 1/5,

We are also told that one-seventh of those taking a computer science course are also taking a mathematics course.

Thus, we can write it as;

P(C|M) = 1/7

According to sets notations, P(M ∩ C) will be the probability that any student is enrolled in both Maths and Computer Science.

Thus;

P(M ∩ C) = P(M|C)P(C) = (1/5)P(C)

Also,

P(M ∩ C) = P(C|M)P(M) = (1/7)P(M)

Equating them, we have;

(1/5)P(C) = (1/7)P(M)

P(C) = (5/7)P(M)

Now; P(M U C) = 1

Let's express out P(M U C)

P(M U C) = P(M) + P(C) - P(M ∩ C) = P(M) + (5/7)P(M) - (1/7)P(M) = (11/7)P(M)

1 = (11/7)P(M)

P(M) = 7/11 = 0.6364 or 63.64%

Otras preguntas