Out of students in a school, it is known that 65% reside in hostel and 35% are day scholars. Previous year results report that 40% of the students who reside in hostel attain A grade and 20% of day scholars attain A grade in their annual examination. At the end of the year, one student is chosen at random from the class.

If the selected student attains grade A, find the probability that the student is a hosteller?

$\frac{26}{33}$

The correct answer is Option (2) - $\frac{26}{33}$