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?
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:
137 comments Page 2 of 14.
Abel lula shonk said:
2 years ago
Thank you everyone.
(9)
Gokulavasan said:
2 years ago
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.
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.
(13)
Prasanth Shanmugam said:
2 years ago
@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.
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.
(12)
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.
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)
Suruthikaa G said:
3 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.
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.
(90)
Abhishek said:
3 years ago
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.
= 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.
(1)
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% 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).
x = 48 + 2/3*48 + 20% of x,
x = 48 + 32 + x/5,
4x/5 = 80,
x = 100 (total number of students).
(16)
Pankaj khati uk 01 said:
3 years ago
No of students above 8 years is 48*2/3 =32,
Then let the total number of students = x,
Then 20%of x is = 20* X /100 = x/5,
Than 48 +32+x/5 = x,
Than x = 100.
Then let the total number of students = x,
Then 20%of x is = 20* X /100 = x/5,
Than 48 +32+x/5 = x,
Than x = 100.
(3)
Vaibhav kumar singh said:
3 years ago
If 20 % = above 8 years so , 80 % = below 8 years + exact 8 years.
therefore 80 % ----> 2/3 of 48=32 (below 8 years) + 48(exact).
80% ---------> 80.
100% ---------> 100.
So, ans = 100.
therefore 80 % ----> 2/3 of 48=32 (below 8 years) + 48(exact).
80% ---------> 80.
100% ---------> 100.
So, ans = 100.
(14)
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