Aptitude - Percentage - Discussion

@Sawant.

= 30/100*x = 180*100/30.

x = (180*100/30)100/30.

x = 270.

@Tukuna Behera.

Why did we take the 25 to the R.H.S, that's the only step I did not understand, help please, or any one, why did we take the 25 to the Right Hand Side?

Option method is too easy and fastest way to solve this question.

Dear @Kavi,

Here we assume that two students mark, one is secured than other in 9 marks.

So let 1st student is x.

2nd student is x+9 [2nd student is secured 9 marks than 1st].

Dear @Chandan it is very simple,

Two students total mark in percentage is 56% that mention in the question.

If we discuss this line the result is x+y = 56%.

But the question says one of them secured 9 marks than other.

So we assume one student is (x+9) and other is x.

Here x+9 means x+9 is secured 9 marks extra than x.

Now if we try to find out the value of x from x+9. If we find out the x output then we must find out both students mark.

x+9 = 56(x+9+x)/100 [here we write 56(x+9+x) means both students percentage is 56%].

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

3x = 99 [25x+225 = 28x+126 => 28x-25x = 225-126 =>3x = 99].

x = 33[x = 99/3 => 33].

Now the original output is:

Two students are: x, (x+9).

1st student's mark is: x = 33.

2nd student is secured 9 marks than 1st student => (x+9) = 33+9 = 42.

Output option is C: 42, 33.

Please clear this.

Correct answer is 42, 33.

How come x+x+9?

He got 9 marks.

Its very simple.

What is the % difference 12% mark difference 9 if 12% = 9; 56%=?

56*9/12 = 42 which is highest mark.

So 42-9 = 33.

Answer is 42, 33.