Pardon me for addressing this post to the list. I see that the solution suggested for question # 1b by Mr. S P Sharma isn't correct and it needs be known to fellow list members so that they can correct themselves. If one multiplies 15000 by 95% twice to get the population 2 years back then the answer is 135375. This answer is incorrect, the correct answer is 13605.
Here's the explanation: Let x be the population 2 years back. 1 year back the population would be: x + 0.05x =1.05x Current year the population would be: 1.05x + (0.05 * 1.05)x =1.05x + 0.0525x =1.1025x Given that current year the population is 15000. So, 1.1025x = 15000 Therefore, x = 15000 / 1.1025 =13605.44 rounded off to 13605. Note that 5% of 100 is 5 but 5% of 95 is 4.75 not 5. So, if the population 1 year back is 95 then current year it would be 95+4.75=99.75 and not 100. The compound interest method suggested by Mr. Vedprakash fits in best for such problems, it's shorter than the above method. I mentioned the above method to explain how it works. Hope this is clear... Best Regards, Zujar. An optimist laughs to forget and a pessimist forgets to laugh! -----Original Message----- From: AccessIndia [mailto:accessindia-boun...@accessindia.org.in] On Behalf Of Vedprakash Sent: Sunday, June 23, 2013 11:25 AM To: accessindia@accessindia.org.in Subject: Re: [AI] help me in understanding the method for solving such type of mathematical problems Sorry for a wrong answer of the second question. sending the same again. 2. In a class 35% students failed in hindi, 45% failed in english subjects respectively. 20% students failed in both subjects, find out the percentage of the students who passed in both subjects. Total numbers of the students: = 100 Failed in Hindi = 35% Passed in Hindi: = 100 minus 35 = 65. Failed in English: = 45 passed in English = 100 minus 45 = 55. failed in both = 20. Passed in either Hindi or English = 100 minus 20 = 80. Passed in Both = A. Passed in either Hindi or English minus Passed in Hindi = 80 minus 65 = 15 Plus B. Passed in either Hindi or English minus Passed in English =80 minus 55 = 25 = A plus B =15 plus25 =40 Answer. ----- Original Message ----- From: "Mohib Anwar Rafel" <mohibra...@gmail.com> To: "accessindia" <accessindia@accessindia.org.in> Sent: Saturday, June 22, 2013 9:34 PM Subject: [AI] help me in understanding the method for solving such type of mathematical problems > Hi friends I am unable to understand the way to solve the following > problems, even I couldn't understand it by reading R. S. Agarwal book. > please guide me. > > 1. If the population of a town is 1,50,000 at present, it is > increasing at the rate of 5% per annum, > (a) what will be the population of the town after 2 years? > (b) what was the population of the town before 2 years? > > 2. In a class 35% students failed in hindi, 45% failed in english > subjects respectively. 20% students failed in both subjects, find out > the percentage of the students who passed in both subjects. > > -- > Mohib Anwar Rafel > M.Phil/Masters in International Law, Center for International Legal > Studies JNU. > Pursuing Masters of Law, at University of Delhi > > Phone: 09811767506, > 01127666896 > > Register at the dedicated AccessIndia list for discussing > accessibility of mobile phones / Tabs on: > http://mail.accessindia.org.in/mailman/listinfo/mobile.accessindia_acc > essindia.org.in > > > Search for old postings at: > http://www.mail-archive.com/accessindia@accessindia.org.in/ > > To unsubscribe send a message to > accessindia-requ...@accessindia.org.in > with the subject unsubscribe. > > To change your subscription to digest mode or make any other changes, > please visit the list home page at > http://accessindia.org.in/mailman/listinfo/accessindia_accessindia.org > .in > > > Disclaimer: > 1. Contents of the mails, factual, or otherwise, reflect the thinking > of the person sending the mail and AI in no way relates itself to its > veracity; > > 2. AI cannot be held liable for any commission/omission based on the > mails sent through this mailing list.. Register at the dedicated AccessIndia list for discussing accessibility of mobile phones / Tabs on: http://mail.accessindia.org.in/mailman/listinfo/mobile.accessindia_accessind ia.org.in Search for old postings at: http://www.mail-archive.com/accessindia@accessindia.org.in/ To unsubscribe send a message to accessindia-requ...@accessindia.org.in with the subject unsubscribe. To change your subscription to digest mode or make any other changes, please visit the list home page at http://accessindia.org.in/mailman/listinfo/accessindia_accessindia.org.in Disclaimer: 1. Contents of the mails, factual, or otherwise, reflect the thinking of the person sending the mail and AI in no way relates itself to its veracity; 2. AI cannot be held liable for any commission/omission based on the mails sent through this mailing list.. Register at the dedicated AccessIndia list for discussing accessibility of mobile phones / Tabs on: http://mail.accessindia.org.in/mailman/listinfo/mobile.accessindia_accessindia.org.in Search for old postings at: http://www.mail-archive.com/accessindia@accessindia.org.in/ To unsubscribe send a message to accessindia-requ...@accessindia.org.in with the subject unsubscribe. To change your subscription to digest mode or make any other changes, please visit the list home page at http://accessindia.org.in/mailman/listinfo/accessindia_accessindia.org.in Disclaimer: 1. Contents of the mails, factual, or otherwise, reflect the thinking of the person sending the mail and AI in no way relates itself to its veracity; 2. AI cannot be held liable for any commission/omission based on the mails sent through this mailing list..
