Aptitude - Percentage - Discussion

Nice explanation @Ramesh.

Nice one @Rumman.

Why we are doing 2/3*48? Please, anyone explain me.

x = total number of students.

Below 8 year = 20%x.
Exact 8 year = 48.
Above 8 year= (2/3) * 48 = 32.
Then the equation becomes (we have to find x):

x = (20%x) + 48 + 32.
x - (20%x) = 80.
100x - 20x = 80 * 100.
x = 100.

Hope you will understand it.

It clearly indicates that 80% of students is 100 but 100% is 120 must be the answer.

I like your method @Showry.

ALTERNATIVELY:.

Let total nos of student be x.

1) Number of Student below 8 years = 20%of x.

2) Number of Student Above 8 years = 2/3 of 48.

3) Number of Student of 8 years = 48.

So, Total students = 20%of x + 2/3 of 48 + 48.

x = 20/100 * x + 2/3 * 48 + 48.
After solving above equation,

x=100.

Thanks @Vinod Anand.

I understand your explanation.

20% of student below 8 year. So, 80% of students above and same age.
Number of students of same age = 48.
Number of students of above 8 is 2/3 of 48.
x is total students.
80% of x = 48 + 2/3 of 48.
x = 100.

FOR You @ANKIT.

LET total no.of students = x.
According to question below 8 years = 20% of x, i.e = 20x/100.

Again acc. to question no.of exact years = 48 and no.of above 8 years = two third of number. exact 8 year i.e = 2/3 of 48 = 32.

Now no.of exact 8 years = 48, above 8 years = 32 and below 8 years = 20x/100.

So total no.of students = 48+32+20x/100 = x(that we have taken at beginning),

So now 80+20x/100 = x,
20x/100 = x-80,
20x = 100x-8000,
100x-20x = 8000,
80x = 8000,
x = 8000/80 = 100(i.e total no.of students) ANS.

I THINK YOU UNDERSTAND..THANK YOU.