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**** Price of a commodity is first increased by x% andthen decreased by x%. If the new price is K/100,find the original price.(a) (x - 100)100/K (b) (x2 - 1002)100/K(c) (100 - x)100/K (d) 100K/(1002 - x?) |
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Answer» Answer: (d) Step-by-step EXPLANATION: LET the original price be a. When it is increased by x%: = > a + x% of a = > a(1 + x%) When decreases by x%: = > a(1 + x%) - x% of a(1 + x%) = > a(1 + x%){ 1 - x% } = > a{1² - (x%)²} {(a+b)(a-b)=a²-b²} In question, new price is k/100: = > a(1² - (x²/100)²) = k/100 = > a(100² - x²)/100² = k/100 = > a(100² - x²) = 100²k/100 = 100k = > a = 100k/(100² - x²) Original price was 100k/(100² - x²) |
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