Question 204140
Let  x  = total  class.
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1st  group  is  70% of  x= .7x,,,,,remainder  is  (1-.7)x = .3x
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2nd group  is  60% of  remainder,,,or .60*.3x = .18x
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final  remainder  is ( 1-.7-.18)x = .12x ,,,(.3-.18=.12 also)
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This  is  12 % of  original
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