Aptitude - Percentage - Discussion

x+9=56/100(2x+9),
How did you reach to this step?

How can you equate both student marks although they have a difference of 9 marks
L.H.S = marks of 2nd student
R.H.S = marks in the percentage of 1st student out of the total sum of the marks scored by both of them.

Please anyone explain it.

Where does this 25 and 14 in equation come? Please explain about it.

@Geetha.

It comes 25/14 when you divide 56/100.

2 numbers are (x) and (x+9).
Now,
(x+9) =56% of (x+x+9),
=(2x+9)56%.

Now open brackets
x+9 = 112x/100 + 504/100,
9 - (504/100 ) = (112x-100x)/100,
(900-504)/100= 12x /100,
396/100 = 12x/100.
>> 396 = 12x.
396/12 = x
33=x,
So 2 digits are:
x = 33,
x+9 = 42.

Answer = C.

1st students marks percentage = 56%,
2nd percentage= 100-56 = 44%,
Difference between marks = 9,
Difference between percentage=56-44 = 12%.
9 = 12% ->1 = 0.75 ->100 = 75(total marks).
56% = 0.75X56 = 42 ,44% = 0.75X44 = 33.

@Vel.

Two students x and y were appear then one get more than 9marks from the other so we take that one member as y as an assumption so y =x+9.

Here we have x and x+9 as two members. Then that x+9 's mark is 56%of sum of their marks. Hence we take (x+9) = 56% (x+ (x+9) ) = option c.

@Pawan.

From the QN, Sum of their mark % is 56%.

Understand the statement :

One of them secured 9 marks more than the other.
So it is (9 + x) , right ?

Next part is " 56% of the sum of their marks"
So here, sum is (x + 9 + x).
And its 56% is (56/100) * (x + 9 + x).

So now, the important part is " .. 9 marks more than the other AND HIS MARKS WAS 56% of ... "

In this line, it says HIS Marks, so whose marks it is ?? It is the marks of ( 9 + x ).
(9 + x ) is the 56% of their sum.

Because of this line, we have equal to symbol in the equation,

So the equation is : (9 + x) = (56/100) * (x + 9 + x).

Thanks @Diksha.

Simple way using ratio.

56 : 44.
i.e 14:11.
33 is divisible by 11 so the answer is C.