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 11 of 14.

Rumman said:   1 decade ago
LET TOTAL STUDENT BE X.

THEN STUDENT BELOW AGE 8=20% OF X=20/100 OF X.

STUDENT EXACTLY AT 8 = 48.

STUDENT ABOVE 8 = 2/3 OF 48 = 32.

20X/100+48+32 = X;
20X+4800+3200 = 100X;

80X = 8000;
X = 100;

SIMPLE.

Pinal patel said:   1 decade ago
Why 48+2/3 of 48?

Sankarshan said:   1 decade ago
What ever may be the % of students below 8 years,

Let x be the no of students below 8 years.
So ,

(2/3)x = 48;
x = (48*3)/2;
x = 72;

So total no of students = 72+48 = 120.

Why this answer is wrong?

Ashish jain said:   1 decade ago
Why 48 is added?

Robin Loomba said:   1 decade ago
Total number of students = x.

According to the condition:
20% of student below 8 years + 48 (8 years student) + (2/3)*48 above 8 years = x (total number of students).

20% of x + 48 + 32 = x.
(20/100)*x + 80 = x.

80 = x-x/5.
80 = 4x/5.

x = 100.

Rupali said:   1 decade ago
Below 8 + equal to 8 + above 8 = total.

20%x + 48 + 2/3*48 = x.

80x = 8000.

x = 100. ANSWER.

VR Chowdary said:   1 decade ago
8< = 20.

8 = 48.

8>90(2/3)*48 = 32.

Total students = 20+48+32 = 100.

DURAI said:   1 decade ago
Total no of students = no.of students below 8 yrs + no.of students exact 8 yrs + no.of students above 8 yrs.

Given data:

no.of students 8 yrs exact = 48.

no.of students above 8 yrs = 2/3 of 48 = 32.

no.of students below 8 yrs = 20.

Answer = 48+32+20 = 100.

Karthik swathi said:   1 decade ago
Here asking the total no.of students, then why u equal to the 80% (which is above 8 year).

Vinod Anand said:   1 decade ago
Let The Total No.of Students are = 100.
So 20% Students are 8 year below = 100X20% /100 = 20.

Than The No.of Students of 8 year below = 20.
And No.of Students 8 year are = 48.

Now No.of Students are above 8 Year = 2/3 X 48.
= 32.

So The Total No. of Students are = 20+48+32.
= 100 , Option (E).


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