document.write( "Question 1182797: When the price of an item was increased by sh.5, I bought 2 items fewer with sh.200.
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document.write( "what is the current price of the item? (It's a kcse question on 1994 pp1 no.16)
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Algebra.Com's Answer #812871 by greenestamps(13200)![]() ![]() You can put this solution on YOUR website! \n" ); document.write( "The number you can buy for sh.200 is 200 divided by the price. \n" ); document.write( "The new price is sh.5 more than the old, so \n" ); document.write( "let x = old price \n" ); document.write( "then x+5 = new price \n" ); document.write( "The number you can buy at the new price is 2 less than the number you could buy at the old price: \n" ); document.write( " \n" ); document.write( "Multiply everything by the least common denominator to clear fractions: \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "x=-25 or x=20; obviously the negative number makes no sense in the problem, so x=20. \n" ); document.write( "The problem asks for the \"current\" (new) price, which is x+5=25. \n" ); document.write( "ANSWER: The current price is sh.25. \n" ); document.write( "Knowing how to solve the problem using formal algebra is important. But if this is a question on a competitive math exam, it's much faster to solve the problem informally. \n" ); document.write( "To do that, write out (on paper if needed; or just in your mind) a list of all the pairs of positive integers whose product is 200; then look for two of those pairs in which one of the numbers differs by 2 and the other differs by 5. \n" ); document.write( "1 * 200 \n" ); document.write( "2 * 100 \n" ); document.write( "4 * 50 \n" ); document.write( "5 * 40 \n" ); document.write( "8 * 25 \n" ); document.write( "10 * 20 \n" ); document.write( "Look at the last two pairs. The 8 and 10 differ by 2; the 25 and 20 differ by 5. \n" ); document.write( "That gives you your answer. For sh.200, you can buy 8 of the items at sh.25 each or 10 of them at sh.20 each. So the current price, at which you can buy 2 fewer of the items than before, is sh.25. \n" ); document.write( " \n" ); document.write( " |