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 13 of 14.
Rahul ghosh said:
6 years ago
Let's total number of students is : x
Below 8 years :: 20 % x
=20/100 * X
= 20X/100.
Others students = X - 20X/100.
= 80X/100.
Absolute, 8 years students = 48.
Above 8 years students = 48 * 2/3.
= 32.
So,
80X/100 = 48 + 32,
X = 100 * 80/80.
= 100.
Below 8 years :: 20 % x
=20/100 * X
= 20X/100.
Others students = X - 20X/100.
= 80X/100.
Absolute, 8 years students = 48.
Above 8 years students = 48 * 2/3.
= 32.
So,
80X/100 = 48 + 32,
X = 100 * 80/80.
= 100.
Kiran BS said:
6 years ago
Let total no of students be X.
Now according to question 20%X + 2/3 of 48 + 48 =X.
On solving the above equation you get X.
Now according to question 20%X + 2/3 of 48 + 48 =X.
On solving the above equation you get X.
Ani said:
6 years ago
For those who are concluding the answer to be 150:
48 is the number of student belonging to 8 years of age, and not the number of students above 8 years of age. This is the confusing part! That's how the answer of total number of students becomes 100.
48 is the number of student belonging to 8 years of age, and not the number of students above 8 years of age. This is the confusing part! That's how the answer of total number of students becomes 100.
Sivagowtham said:
6 years ago
20%.
100-20 = 80% of X.
48*2/3 = 32,
48+32 = 80,
80% of X = 80.
X = 100.
100-20 = 80% of X.
48*2/3 = 32,
48+32 = 80,
80% of X = 80.
X = 100.
Prasad M said:
6 years ago
2/3 of 48 -> 32.
32(above 8 years)+48 ( =8 years ) = 80.
From the question rest 20 percent is below 8 years age and is 20 because 80 students already came is assumed to be 80 percent.
: 80+ 20 = 100.
32(above 8 years)+48 ( =8 years ) = 80.
From the question rest 20 percent is below 8 years age and is 20 because 80 students already came is assumed to be 80 percent.
: 80+ 20 = 100.
Sneha rodke said:
5 years ago
80 %x = 48 + 2/3 * 48.
Then why 48 is again added. It's is only said in the question that 2/3 of no of students with the age of 8 years. Can someone explain?
Then why 48 is again added. It's is only said in the question that 2/3 of no of students with the age of 8 years. Can someone explain?
Jiya said:
5 years ago
Below 8 years = 20.
Exact 8 years = 48.
Above 8 years = 2/3*48 = 32.
Now add 48+32+20=100.
Exact 8 years = 48.
Above 8 years = 2/3*48 = 32.
Now add 48+32+20=100.
Swathi krishna.b said:
5 years ago
Exact 8 years = 48.
Above 8 years age=2/3*48=32.
Then, 20% of the students below 8 years, so 80% of the students are 48+32=80.
80---------->80
20---------->?.
80 * 20/80==>1600/80=20.
So, the total number of students is 32+48+20=100.
Above 8 years age=2/3*48=32.
Then, 20% of the students below 8 years, so 80% of the students are 48+32=80.
80---------->80
20---------->?.
80 * 20/80==>1600/80=20.
So, the total number of students is 32+48+20=100.
Anusha said:
5 years ago
Thanks, @Sravan!
Pavi said:
5 years ago
Let,Total no of students= 100.
20% are below 8,
So, (20/100)*100 = 20,
At 8,
48 members.
Above 8,
2/3 *48 = 32.
Total students = 20 + 48 + 32.
=100.
20% are below 8,
So, (20/100)*100 = 20,
At 8,
48 members.
Above 8,
2/3 *48 = 32.
Total students = 20 + 48 + 32.
=100.
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