Question

At a given high school, the probability that a student is taking a geometry class is 0.24. The probability that a student is taking a chemistryclass and a geometry class is 0.18.If a student is taking a geometry class, what is the probability that the student is also taking a chemistry class?

Answer 1

Consider that the probability that a student is taking both geometry and chemistry class is the product of the probability for geometry class by the proability for chemistry class.

If the probability that a student is taking a chemistry

class and a geometry class is 0.18, and the probability that a student is taking a geometry class is 0.24, you have:

0.24x = 0.18

where x is the probability a student is taking a chemistry class.

Solve the previous equation for x:

0.24x = 0.18 divide by 0.24 both sides

x = 0.18/0.24

x = 0.75