Of the students in a college, it is known that 60% reside in a hostel and 40% do not reside in hostel. Previous year results report that 30% of students residing in hostel attain A grade and 20% of one’s not residing in hostel attain A grade in their annual examination. At the end of the year, one students is chosen at random from the college and he has an A grade. What is the probability that the selected student is a hosteller?

Explanation

Let, `A` be grade,

`H=` hostel

`D=` day scholar


Given,

`P(A/H)=0.3`


`P(A/D)=0.2`


`P(H)=0.6`

`P(D)=0.4`


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