A watch was sold at a profit of 15%. If its cost had been 5% less and it had been sold for Rs. 21 less, than the profit would have been 10%. Find the cost price of the watch

• Better to avoid algebraic method as it consumes more time .
  So let cost price =100
  then 1st selling price =115(profit 15%)
  
  the second cost price =95(cost price is 5% less)
  then second price =95+10% of 95=104.50
  
  therefore the difference in selling price =115-104.50=10.50
  bt actual difference is 21
  
  if difference is 10.50 the cost price=100
  if difference is 21 the cost price =(100/10.50)*21=200
  so x =200 (answer)
  
• 10 years agoHelpfull: Yes(116) No(1)
• let the price of the watch is x
  it was sold at a profit of 15%
  then the price of the watch is 1.15x
  again cost had been decreased by 5% i.e 0.95x
  according to the question
  1.15x=0.95x*(110/100)+21
  then x=200
• 10 years agoHelpfull: Yes(23) No(0)
• Let the cost price be x
  S.p.=(1+.15)x
  New c.p.=.95x
  New s.p=(1+.1).95x
  By given question
  (1+.15)x-(1+.1).95x=21
  X=21/(1.15-1.045)=21/.105=200
  Cost of watch=200
  
• 10 years agoHelpfull: Yes(16) No(1)
• let us consider cp is x
  sp=x+15%x=x+15/100x=23/20x
  if cost price is reduced by 5% means new cp= x-x/20=19/20x
  sp is reduced by 21 means new sp=23/20x-21
  profit is 10% means 10/100* 19/20x=19/200x
  from data
  sp-cp=profit
  23/20x-21-19/20x=19/200x
  230x-190x-19x/200=21=> 21/200x=21 =>x=200
  so cp=200
• 10 years agoHelpfull: Yes(6) No(2)
• the way gauri modani explained was superb....keep it up gauri
• 9 years agoHelpfull: Yes(3) No(0)
• s.p=115/100*c.p........................(1)
  s.p-21=110/100 (c.p-5/100 c.p)
  put value of s.p from (1) in (2)...
  115/100*c.p-21=110/100 (c.p-5/100 c.p)
  solve it and c.p comes=Rs 200
• 9 years agoHelpfull: Yes(0) No(0)
• 10/21*100=
• 9 years agoHelpfull: Yes(0) No(0)