In a college, 40% of the students were allotted group A, 75% of the remaining were given group B and the remaining 12 students were given group C. Then the number of students who applied for the group is :

Let total number of student apply in college 100x
40% student alloted in group A , i.e. 40x
Remaining Student 100x - 40x = 60x
Now 75% of remaining student got alloted in Group B
i.e. 75% of 60x = 45x
Remain student is 60x - 45x = 15x (which alloted in Group C)
According to question
15x = 12
x = $$ \frac{12}{15} $$
Total Number of Student applied in college = 100x
= 100 x $$ \frac{12}{15} $$
= 80