A towel, when bleached, was found to have lost 20% of its length and 10% of its breadth. The percentage of decrease in area is:

A. 10% B. 10.08%
C. 20% D. 28%

• Option D 28%
  Let the length is l and breadth is b
  Now the length becomes 0.8*l and breadth is 0.9*b
  so the area=0.8*.9lb=.72 lb
  So change in area=1-.72/1*100
  =.28*100=28%
• 12 years agoHelpfull: Yes(2) No(1)
• 28%
  %change= %increase- %decrease -%increasex%decrease/100
  -20 - 10- (-20) x (10)/100
  =150 %
  Req percentage = 150%-100%=28%
• 11 years agoHelpfull: Yes(2) No(1)
• 28%
  
  let the length=100 and breadth= 100, so area =l*b i.e 100*100= 10000
  
  after bleaching length=80 and breadth= 90, so new area is 80*90= 7200
  
  decrease in %age= (10000-7200/10000)*100= 28%
  
• 9 years agoHelpfull: Yes(0) No(0)
• orginal 100*100=10000
  remain l*b=80*90=7200
  orginal-remain=28000
  28000/10000*100=8%
• 7 years agoHelpfull: Yes(0) No(0)