Question

In a group of 200 students 40 are taking English,50 are taking
mathematics,and 12 are taking both.
(a) If a student is selected at random, what is the probability that the student
is taking English?
(b) A student is selected at random from those taking mathematics. What is
the probability that the student is taking English?
(C) A student is selected at random from those taking English, what is the
probability that the student is taking mathematics?​

Answer 1

Step-by-step explanation:

The question is of conditional probability .

p(A) = 40/200

p(B) = 50/200

p(A intersection B ) = 12/200

i)P(A) = 0.2

ii) in second question there is asked directly that students are being selected from those taking math ( it has been done ) we have to find probability that student is taking english ( to be finded ).

formula :

p(A|B) = p(A intersection B)/ p(B)

sol :

p(A|B) =

\frac{12}{200} \times \frac{200}{50}

200

12

×

50

200

(multiplication rule)

=

\frac{12}{40}

40

12

=0.24

iii) third is also the same its like

p(B|A) = p(A intersection B) / p(B)

( solve by yourself)