Aptitude - Percentage - Discussion

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.

2/3(students of 8 years age) = 48.
So number of age of 8 years students is 48*3/2 = 72.
And number of students above 8 years age is 48.

So we can conclude 80% of students of class is 72+48 = 120.
Therefor 100% of students number become 120*100/80 = 150.
So students of below 8 years age is 30.

I think the answer is 150.

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 % = 48 + 2/3 * 48.
48 + 32 = 80 students,
80 % = 80 students,
20 % = x students.

Cross multiple;
We get 20 students,
For 20% students = 20 students,
Hence 20 % + 80 % = 20 + 80 students,
Total no of students = 100 students.

1. Let us assume the total number of students be 100%.
2. Then subtract 20% from 100% (where 20% equals less than 8 yrs).
3. Given exact 8 years child = 48.
4. A/Q above 8 years will be 2/3 of 8 years which means (2/3'-48=32).
5. Add exact 8yrs+above 8yrs =80 which is also equal to 80'.
6. Then 100 Will be 80'-100/80=100 students (Total).

Let us assume that total number of students =100%-20%=80%.
2/3 this means 3 parts *16=48
then 2parts * 16 = 32.
Together 80%= 48 + 32.

100% = 100 students.

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.

80% of x = 48 + 2/3 of 48 ,how to came this i dont know any one can tell?

80% of x (means no of student havin age, 8 and above ) = 48(no of student of age =8)+2/3 of 48(studens abov age 8)

look this....

Total no of students
S = (age < 8) + (age = 8) + (age > 8)

age < 8 = 20%(S) ====> 20S/100
age = 8 ====> 48
age > 8 ====> (2/3)*48 ====>32

S=20S/100 + 48 +32

S=100