Aptitude - Percentage - Discussion

An important interview question:

Question: 75% of a number when added to 75 becomes the number itself. The number is ?

Solution:

Let the required number be x.

x = 75% of x + 75

x = 75/100x + 75

1x = 0.75x + 75

1x - 0.75x = 75

0.25x = 75

x = 75/0.25

x = 7500/25

x = 300.

Verification:

75% of 300 = 275
Now 755 + 75 = 300

Hence 300 is the required answer.

Hey the correct answer is option d.55%
explaination:x%of a number is given as :(x*number)/100 and not (x*100)/number..
for eg 10%of 20 is 2...therefore according to my formula its (10*20)/100=2 but according to the way the sum has been solved here its (10*100)/20=50...which is wrong how can 50 be 10%of 20????
therefore here its (50*110)/100=55%

Can please solve problems with explanation?

If 12 1/2% of a 25% of b = 20% of (a+b), Then what is the ratio of b:a?

@Jay

1 : 2 is answer.

Let me explain.

Total runs made by him = 110 in which he made 3 boundaries and 8 sixes
So basically a boundary means 4, therefore 3 boundaries means 3 X 4 = 12.
And 8 sixes equals to 8 X 6 = 48.

Now adding boundary and sixes made by him,
Therefore 12 + 48 = 60.

So the score 60 was not made by runs.

So let us subtract the score 60 from the total score 110.
So that 110 - 60 = 50
50 is the score which is made by running between the wickets.

The solution is not yet completed, it's about to finish

We need to get a percentage of that runs made by him.

50/110 * 100 = 45 * 5/11 will be the answer.

Hope you understand.

How come 45? Please tell me.

Can any one say this type of questions will comE for IT industry

How does 4 come in multiply? Explain, please.

Thanks @Aparna.

110 - (3 * 4 + 8 * 6)/110 * 100 = 500/11.