Aptitude - Percentage - Discussion

Discussion Forum : Percentage - General Questions (Q.No. 2)
2.
Two students appeared at an examination. One of them secured 9 marks more than the other and his marks was 56% of the sum of their marks. The marks obtained by them are:
39, 30
41, 32
42, 33
43, 34
Answer: Option
Explanation:

Let their marks be (x + 9) and x.

Then, x + 9 = 56 (x + 9 + x)
100

25(x + 9) = 14(2x + 9)

3x = 99

x = 33

So, their marks are 42 and 33.

Discussion:
173 comments Page 5 of 18.

Uttam said:   1 decade ago
First find total marks

difference between percentage=56%-44%=9%

In the question given difference between marks as 12

so, if mark is percentage

9 12%

? 100%

so by cross multiplying total marks=(9*100)/12=75.

now student 1s marks=56% of 75 i.e

(56/100)*75=42.

student 2s marks=44% of 75 i.e

(44/100)*75=33.
(2)

Radhika said:   1 decade ago
56-44/100=9
12/100=9
=75
now
56/100*75=42
44/100*75=33
:)
(2)

Ganesh said:   1 decade ago
very 1 stape is just to calculate total marks in each option,
suppose, I'm choosing 39 30 then total marks are 69 which is 100% if u calculate 56% of 69 i.e 56*69/100 you get 38.64 which is not in option. so leave it there.

if you're taking 42 33 then total marks are 75 which is 100% and 56% of 75 is 42 hence option C is correct.

though it is lengthy procedure, we can choose the option for calculation by little thinking before solving it.
(2)

Preetika said:   4 weeks ago
How 25 has come? Please explain to me.
(2)

Srabani guntha said:   2 weeks ago
Let the student are;
a,b and their marks are x and x+9
As the question is given,
from the question we get.
x+x+9(56/100) = x+9.

Because the question is said 56 per cent of the sum of their mark;
So 2x+9 (56/100) = x+9,
(112x +504)/100 = x + 9,
112x +504 = 100x + 900,
112x-100x = 900 - 504.
12x = 396.
x = 33.
and x + 9 = 33 + 9,
= 42.

So the mark are 33 and 42.
(2)

Aparna said:   1 decade ago
Suppose 1 students score is 'x',then others will be 'x+9'

Now the next information is given about the student whose score is 'x+9'

Whenever in the question 'and'/'is' given put '=' sign
56% means 56/100 ,of means put multiplication sign
and sum of the marks means(x+x+9)

Now just solve the equation.
(1)

Vel said:   1 decade ago
Ok why equal sign assigned b/w x+9 and 56/100 (x+9+x) ?
(1)

Prasad said:   1 decade ago
@aparna..Hi..could it possible to put in details.please
(1)

Krishna said:   1 decade ago
@uttam

How it can be 56%-44%=9%?

Can you explain it?
(1)

Neelu said:   1 decade ago
Let mark of person A = x.
Mark of person B = x+9.

Total marks secured by both A & B = x+(x+9).
Since %mark of person B = 56/100(x+(x+9)).
Therefore x+9 = 56/100(x+(x+9)).

x+9 = 14/25(2x+9).
25(x+9) = 14(2x+9).
25x+225 = 28x + 126.
28x-25x = 225 - 126.

3x = 99.
x = 99/3.
x = 33.

Hence mark of person A = 33.
Mark of person B = 33+9 = 42.
(1)


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