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voodoo_child
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The price of a radio decreased m percent between 2010 and 2011 and then increased n percent between 2011 and 2012. Was the price of the automobile lower in 2010 than in 2012?
1) m<n
2) mn<100(n-m)
Here's what I did:
2010 :X = price of the radio
2011 :(1-m)X
2012 : (1-m) (1+n) X
Question : Is X< X(1-m)(1+n)?
Solving above equation, we get Is n-m>mn?
now, if m=0.2; n-0.2>0.2n => 0.8n>0.2 => n>0.25 (required)
1) m<n => if m=0.2; n>0.2 Not sufficient
2) mn <100(n-m) => 0.2n<100 (n-0.2) => 0.2n < 100n - 20 => 20<99.8n => n>0.2004
I ended up finding the same equation for 'n'. However, OA is B.
Can someone please tell me what's wrong with my method?
1) m<n
2) mn<100(n-m)
Here's what I did:
2010 :X = price of the radio
2011 :(1-m)X
2012 : (1-m) (1+n) X
Question : Is X< X(1-m)(1+n)?
Solving above equation, we get Is n-m>mn?
now, if m=0.2; n-0.2>0.2n => 0.8n>0.2 => n>0.25 (required)
1) m<n => if m=0.2; n>0.2 Not sufficient
2) mn <100(n-m) => 0.2n<100 (n-0.2) => 0.2n < 100n - 20 => 20<99.8n => n>0.2004
I ended up finding the same equation for 'n'. However, OA is B.
Can someone please tell me what's wrong with my method?
