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:
135 comments Page 3 of 14.
Poojitha said:
4 years ago
@Moorthy.
100% - 20% whose age are below 8 = 80%.
Now remaining part is given in that sub part is 48 people are equal to 8 years of age.
And tge people who are in between 8 years I. E in between of equal to 8 and below 8 is 2/3 of 48.
Total = below 8 years + equal to 8 years + more than 8 years = 100.
100% - 20% whose age are below 8 = 80%.
Now remaining part is given in that sub part is 48 people are equal to 8 years of age.
And tge people who are in between 8 years I. E in between of equal to 8 and below 8 is 2/3 of 48.
Total = below 8 years + equal to 8 years + more than 8 years = 100.
Priyanka Gupta said:
9 years ago
ALTERNATIVELY:.
Let total nos of student be x.
1) Number of Student below 8 years = 20%of x.
2) Number of Student Above 8 years = 2/3 of 48.
3) Number of Student of 8 years = 48.
So, Total students = 20%of x + 2/3 of 48 + 48.
x = 20/100 * x + 2/3 * 48 + 48.
After solving above equation,
x=100.
Let total nos of student be x.
1) Number of Student below 8 years = 20%of x.
2) Number of Student Above 8 years = 2/3 of 48.
3) Number of Student of 8 years = 48.
So, Total students = 20%of x + 2/3 of 48 + 48.
x = 20/100 * x + 2/3 * 48 + 48.
After solving above equation,
x=100.
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.
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)
Ashoka said:
8 years ago
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.
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.
(1)
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.
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)
Arun said:
6 years ago
No answer is 100.
Below 8 years is 20%.
Above 8years is 2/3rd of 48 (48= exact age of 8years).
2/3 rd =32.
So total students is age below 8 exactly 8 and above 8.
=48+32+x,
=80+x.
Below 8 years and exactly 8 years are 80%.
remaining are 20% i.e below 8 years =20.
Which gives 100.
Below 8 years is 20%.
Above 8years is 2/3rd of 48 (48= exact age of 8years).
2/3 rd =32.
So total students is age below 8 exactly 8 and above 8.
=48+32+x,
=80+x.
Below 8 years and exactly 8 years are 80%.
remaining are 20% i.e below 8 years =20.
Which gives 100.
Debasmita said:
1 decade ago
Answer should be 150.
Explanation:
Let, x = no. of student at 8 years old.
Above 8 years old = 2/3 of x.
=> x = 48*(3/2) = 72.
Students above 8 years and 8 years old = 72+48 = 120.
If (100-20)% = 80% equals 120 students.
1% equals 120/80.
100% equals (120/80)*100 = 150.
Explanation:
Let, x = no. of student at 8 years old.
Above 8 years old = 2/3 of x.
=> x = 48*(3/2) = 72.
Students above 8 years and 8 years old = 72+48 = 120.
If (100-20)% = 80% equals 120 students.
1% equals 120/80.
100% equals (120/80)*100 = 150.
Abhishek said:
2 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)
Jeevana Sravanthi said:
7 years ago
My answer is 120.
Because, there is no condition like,
No.of students(age>8) = (2/3) * no.of students (age=8).
Its more like:
No.of students(age>8) = no.of students (age=8),
So,
80% of students =(age>8)+(age=8) =48+48=96,
100% of students = 96/0.8 = 120.
Because, there is no condition like,
No.of students(age>8) = (2/3) * no.of students (age=8).
Its more like:
No.of students(age>8) = no.of students (age=8),
So,
80% of students =(age>8)+(age=8) =48+48=96,
100% of students = 96/0.8 = 120.
Saifz said:
1 decade ago
20% of students out of 100 % are below 8 years, so remaining is 80% = 48 which they are above 8 years or exact 8 years. lets take 80% of students =48
If 80%=40
then 100%=?
i.e 100*48/80=60
and 2/3 of 60=40
Hence total students in class form eq1 and eq2 60+40=100
If 80%=40
then 100%=?
i.e 100*48/80=60
and 2/3 of 60=40
Hence total students in class form eq1 and eq2 60+40=100
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