# The probability of Ann passing her math test is 90%. The probability she passes her English test is 80%. The probability she passes her Chemistry test is 70%. What is the probability she passes all three tests?

Jan 31, 2017

50.4%.

#### Explanation:

Let $M =$ the Event that Ann passes Maths. Test.

$E \mathmr{and} C$ denote the Events of her passing in English and

Chemistry Tests, resp.

Then, we are given that,

P(M)=90%=9/10, P(E)=8/10, &, P(C)=7/10.

$\text{The Reqd. Prob.=} P \left(M \cap E \cap C\right) .$

Since, the Events are Independent, the Reqd. Prob.

$= P \left(M\right) P \left(E\right) P \left(C\right)$

$= \left(\frac{9}{10}\right) \left(\frac{8}{10}\right) \left(\frac{7}{10}\right)$

$= \frac{504}{1000}$

=50.4%.