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:
140 comments Page 4 of 14.
M.Lokesh said:
4 years ago
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.
2/3 this means 3 parts *16=48
then 2parts * 16 = 32.
Together 80%= 48 + 32.
100% = 100 students.
(1)
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)
Moorthy said:
2 decades ago
80% of x = 48 + 2/3 of 48 ,how to came this i dont know any one can tell?
Prawin said:
2 decades ago
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)
Showry said:
2 decades ago
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
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
Rishi said:
2 decades ago
How 2/3 comes in abve 8 year students
Sravanreddypailla said:
2 decades ago
Let total=x
exact 8 years = 48
above 8 years = 2/3*48 = 32
so 48+32= 80
given 20% below 8 years therefore reamaining i.e above n exact=80%
from above 80%=80
that means 20%=20(default as we take percentage in hundredths)
TOTAL OF THE ABOVE =100
exact 8 years = 48
above 8 years = 2/3*48 = 32
so 48+32= 80
given 20% below 8 years therefore reamaining i.e above n exact=80%
from above 80%=80
that means 20%=20(default as we take percentage in hundredths)
TOTAL OF THE ABOVE =100
Rahul said:
2 decades ago
@Ramesh
Below 8 years is 20% not 20 its not work out in all problems.
Below 8 years is 20% not 20 its not work out in all problems.
Ayesha said:
1 decade ago
Ramesh method is very good I liked that.
Romita said:
1 decade ago
Thanks ramesh.
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