Aptitude - Percentage - Discussion

Given;

20% below 8 year of age. (100%- 20% ) = 80%.
80 % = age of students equal to 8 yr + age of students above 8 yr.
80 % of Total students = 48 + 2/3 * 48.
80% of Total students = 48+32 = 80
(80/100)* Total students = 80
Total Students = 80 *(100/80) = 100.

The number of students having an age greater than or equal to 8 = 48 + 2/3*48.
= 48 + 32=80.

Given 20% of students are below 8 years of age.
So, just reduce the number of students having ages less than 8.
0.80 * x = 80 (after reducing 20%students so that's why 0.80).
x = 100.

Simply;

Students below age of 8= 20%
Students above age of 8= 2/3,
Students in age of 8= 48.
48*2/3= 32.
32+48= 80%.
80%+20%=100%.
So, 100 students.

Below 8y= 20%,
8 y= 48.
Above 8 y=2/3 of48 = 32.
Let no.of students be x.
20% x = x - 80,
20/100x = x - 80,
80 = x - 20/100x.
x = 100.

@All.
Here is my solution.

Total Number of Students = X.
Less than 8 Years age Students = 20 % of X = (20/100) * X.
8 Years Age Students = 48,
c = (2/3) * 48 = 32.

Total Number of Students = X = Less than 8 Years age Students + 8 Years Age Students + 8 Years Age Students
X = (20/100) * X + 48+32.
X = (20/100) * X + 80.
X = (20X+8000)/100.
100X = 20X+8000.
80X = 8000.
X = 8000/80.
Total Number of Students = X= 100.

Below 8 years is 20%.
Above 8 and equal to 8 years is 80%.

The number of students above 8 years of age is 2/3 of the number of students of 8 years of age which is 48.

1/3 of 48 students is 16.
2/3 of the students are 32.
1/3+2/3 = 48 (8 years).
16 students (above 8 years),
48 + 32 = 80 equal and above 8 years,
80% = 80 then,
20% = 20.
Total 100 students.

Thank you everyone.

8 years below = 20%.
8 years above= ⅔ x 48 is 32.
8 years = 48.
Total students = 100%.

Then, 8 years above + 8 years below + 8 years = 100%.
20%. Below the rest 80%,
80% = 32+ 48,
80% = 80.
Then 100 % = 80/80 = 1.
20%= 20.
Total students 20 + 32 + 48 = 100.

No.of students of 8 yrs - 48.
No.of students of above 8 yrs - 2/3 of 8 yrs old stud.
So, 2/3*48 = 32.
Total students of 8 yrs and above 8 yrs = 48 + 32 = 80 students.

Now, out of the total students, only 20% of them are below 8 years old. We don't know how many are total students yet. So let's assume the total students as X.
Students below 8 years old -X*20/100(20% is written as 20/100).
= 20x/100.

Total students in school,
80(8yr & above 8 yr total) + 20x/100(below 8yrs total) = x(total students in school that we assumed as x).
80 + 20x/100 = x.
//Take LCM for 80+20x/100.
(8000+20x)/100 = x.
//Bring the denominator 100 to the right side to multiply with x.
8000 + 20x = 100x.
8000 = 80x.
x = 100.

Let,
The no of students = 100
Now, 20% of 100 =20
Above 8 years old are = 48
And 8 years old are :
2/3 of 48
= 32.

Now, the total no of students are: 48 + 32 + 20 = 100.