# Something based on Perentage. [closed]

A candidate who gets 20% marks in an examination fails by 30 marks but another candidate who gets 32% gets 42 marks more than the passing marks. Then the percentage of pass marks is:

1. 52%
2. 50%
3. 33%
4. 25%
• Note that you don't even have to do any calculations here; only one choice could possibly be right. Dec 28, 2016 at 17:17
• You should explain what you don't get and explain what you have tried. This is insulting. Dec 28, 2016 at 17:19
• Haha, nice observation @pjs36. Anyways Shubham, if you wanna solve it nonetheless, it is a simple case of a system of two linear equations with two variables, passing marks and total marks. Dec 28, 2016 at 17:21
• Thank you for copy-pasting your homework assignment into our service. Please stand by while our neural-network algorithm is auto-generating an answer to your question. One of our representatives will be with you shortly. On the meanwhile, please prepare your 16-digit credit card number, including your full name, expiration date and those 3 digits on the back of the card which for some reason are not on the front with the rest of them. Since this is a social-network web service, the cost will be 1 bitcoin per user. Thanks again for choosing to work with us. Dec 28, 2016 at 17:56
• Sorry people. I think I have ended up at the wrong place. I was simply looking for a site where any question can be discussed without considering the asker's ability and capability. This place is good, but, not for what I am looking for. Anyways, I got an explanation and an insight view into my question. And, I was not copy pasting my homework or something. I was simply looking for someone, may be at the wrong place, who could have simply explained this to me without any extra comments. Wrong Place Wrong Time Dec 28, 2016 at 19:09

If you fail at 20% and pass at 32% the percentage at which you pass is between these. Only one option satisfies this.

Otherwise solve the system:

$$0.2x = y - 30 \\ 0.32x = y+42$$

And show your work next time, this is not a homework service.

• I gracefully accept your explanation. Dec 28, 2016 at 18:57
• You showed me a simple way to look into such questions. I guess, I wont be solving them as equations when I encounter them again. Sir, thanks for your explanation. Dec 28, 2016 at 19:00
• And, sir, don't mind me but I guess I have not asked for any kind of home-work service. I asked for an insight view and I am happy to have received that from your side. Dec 28, 2016 at 19:02
• I'm sorry if I offended you, you must understand that a very high percentage of these kinds of questions are people posting homework problems, and in general, questions (even easier ones) are welcome if you show your own attempt. Glad I could help. Dec 28, 2016 at 22:14
• I get it sir. I guess, from next time onwards I will be clearly mentioning where I got stuck and I will show my approach too instead of simply asking it. Dec 29, 2016 at 8:20

Passing marks = 20% of x + 30 ....(1)

As he needs 30 more marks wo added.

Passing marks = 32% of x - 42 .....(2)

As he has 42 more marks then passing so subtracted.

From (1) and (2)

20% of x + 30 = 32% of x - 42

32% of x - 20% of x = 30 + 42

12% of x = 72

x = $\frac{72 * 100}{12}$

x = 600

So total marks 600.

From equation (1)

Passing marks = 20% of x + 30

= $\frac{20}{100}$ * 600 + 30 = 120 + 30 = 150

Passing percentage = $\frac{150}{600} * 100$ = 25%

• good explanation. Thanx Dec 29, 2016 at 12:27