A School has $2000$ students,out of which $40$% of the students are in higher secondary.Out of the students in the higher secondary, $28$% are girls and $50$% of them passed.The overall pass percentage in the higher secondary is $40$%. How many boys passed?
My approach
School has $2000$ students,$2$/$5$ of students are in HS.$7$/$25$ of students are girls.This means,$18$/$25$ of students are boys.
And,$7$/$50$ of girls are passed.(because $1$/$2$(50%) . $7$/$25$ )
How many boys passed(=Let's say x).
Overall percentage=$40$%.
$7$/$50$ + x=$40$%.
I am not getting any link between the relations I have formed.
Can anyone guide me how to solve the problem?
Best Answer
Don't work with fractions and relative numbers. Work with absolute numbers, that makes things easier.
40% of students are in HS, thus 800 students.
Of those, 28% are girls, thus 224 girls. And half of them passed on the test, thus 112.
On the other hand, of those 800 students, 40% passed, thus 320.
Of those 320-112=208 are boys.