Aptitude - Percentage - Discussion

Discussion Forum : Percentage - General Questions (Q.No. 7)
7.

In a certain school, 20% of students are below 8 years of age. The number of students above 8 years of age is of the number of students of 8 years of age which is 48. What is the total number of students in the school?

72
80
120
150
100
Answer: Option
Explanation:

Let the number of students be x. Then,

Number of students above 8 years of age = (100 - 20)% of x = 80% of x.

80% of x = 48 + 2 of 48
3

80 x = 80
100

x = 100.

Video Explanation: https://youtu.be/yPfocU6DA2M

Discussion:
135 comments Page 1 of 14.

Suruthikaa G said:   2 years ago
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.
(88)

Khirod said:   2 years ago
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.
(58)

Lily said:   1 year ago
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.
(57)

Bimal said:   9 months ago
Let students <8 = 20%.
Let students >8 = 2/3(48).
Let students who are 8 = 48.

Now let's calculate students >8,
which is 2/3(48)=96/3=32

Now combine students who are >8 and students who are 8.
which is 32 + 48 = 80.

Now we have to find student <8 which is 20% of the whole class
We got the remaining 80% which is 80. so what percent should be added with 80% to make it 100%?
It is 20%.

So if 80% is 80 then 20% is 20.
which is total students 80 + 20 = 100.
(29)

JAYASURYA P said:   7 months ago
8 years below student = 20%
assume total percentage = 100%
8 years student(given) = 48.

8 years above = remaining of below 8 years student.
so 100%-20%= 80%.
then, 80(above 8 years).
student=(above + below + same level).
So, 80-48(same 8 years) = 32(above 8 years).
Total = 20 + 32 + 48 = 100.
(27)

Aruna B said:   2 years ago
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.
(23)

Pappa said:   8 months ago
20% + 48 = 68.
100 - 68 = 32.
20 + 32 + 48 = 100.
(23)

Krushna said:   3 years ago
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.
(20)

Hemant Asthana said:   3 years ago
x is a total number of students. Then According to the question,
x = 48 + 2/3*48 + 20% of x,
x = 48 + 32 + x/5,
4x/5 = 80,
x = 100 (total number of students).
(16)

JPE said:   2 years ago
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.
(15)


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