if length of a rectangle is incr by 20% and width is decr by 20% then area

2 Answers on this Question

1. we know,
   area=b*h
   b gets increased by 20% i.e (b+0.20b)
   h gets decreased by 20% i.e (h-0.20h)
   rewriting the equation(area=b*h),
   area=(b+0.20b)*(h-0.20h)
   area=b(1+0.20)*h(1-0.20)
   area=b(1.20)*h(0.80)
   area=b*h*(1.20)*(0.80)
   area=b*h*(0.96)
   i.e new area=0.96 times the original area
   if 100% was the original area,it has decreased to 96%
   so,100%-96%= 4%

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2. Decreased by 4%
   Refer GMAT’96 edition ..i think page 44

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