In a school 40% of students are boys and remaining are girls .75% of boys and 60% of girls have passed the
examination. If the no. of boys passed the exam is 180. Find the no. of girls who failed in exam?
Answers
Question:
In a school 40% of students are boys and remaining are girls. 75% of boys and 60% of girls have passed the examination. If the no. of boys passed the exam is 180. Find the no. of girls who failed in exam?
Answer:
144
Solution:
Let the total no. of students in the school be x .
Also,
It is given that, 40% of students are boys.
Thus,
=> Total no. of boys = 40% of x
=> Total no. of boys = (40/100)•x
=> Total no. of boys = (2/5)•x
=> Total no. of boys = 2x/5
Since,
40% of students are boys , hence it is clear that 60% of students are girls.
Thus,
=> Total no. of girls = 60% of x
=> Total no. of girls = (60/100)•x
=> Total no. of girls = (3/5)•x
=> Total no. of girls = 3x/5
Now,
It is given that , 75% of boys (180 boys) have passed the examination.
Thus,
=> The no. of boys who passed the examination
= 75% of (total no. of boys)
=> 180 = 75% of (2x/5)
=> 180 = (75/100)•(2x/5)
=> 180 = (3/4)•(2x/5)
=> 180 = (3•2x)/(4•5)
=> 180 = 6x/20
=> x = 180•(20/6)
=> x = 30•20
=> x = 600
Hence,
The total no. of students in the school is 600.
Also,
Total no. of girls in the school
= 3x/5
= 3•600/5
= 3•120
= 360
Now,
No. of girls who passed the examination
= 60% of (total no. of girls)
= (60/100)•360
= 60•360/100
= 6•36
= 216
Now,
No. of girls who failed in the examination
= (Total no. of girls) - (no. of girls who passed)
= 360 - 216
= 144
Hence,
The number of girls who failed in the examination is 144 .
Answer:
In School 40%of students are boys out of which 75% of boys passed the exam
No of boys passed =180
let total no of boys and girls be x
So, No of boys passed =40% of 75% of x
=0.4×0.75 x
=0.3x
0.3x =180
x=600
60% girls passed
So, 40% girls failed exam
Total 60% are girls
So, No of girls failed exam =60% of 40%of 600
=0.6 ×0.4×600
=144
So,No of girls failed exam =144