Radha bought a watch for Rs. 144 and got a percentage of profit equal to the cost price of the watch. What is the cost price of the watch?
Option
A) Rs. 72
B) Rs. 78
C) Rs. 80
D) Rs. 90

• SP=144
  CP=x
  profit %=x
  C.P.= (100/(100+gain%))*S.P.
  x=(100/100+x) *144
  x^2+100x=14400
  x^2+180x-80x-14400=0
  (x+180) (x-80)=0
  x=-180
  x=80
  so answer is c. Rs. 80
• 10 years agoHelpfull: Yes(47) No(1)
• C. Rs. 80
  If Cost Price=x
  x+(x*x/100)=144, x^2+100x-14400=0
  (x-80)(x+180)=0, x=80
• 10 years agoHelpfull: Yes(9) No(0)
• profit = sp-cp
  if cp = profit then
  sp = 2 cp
  nw sp=144.
  so 144= 2cp
  cp= 72.
  cp=72
• 10 years agoHelpfull: Yes(8) No(30)
• Trying to solve with d help of options
  80℅ of 80 is 64 and 80+64=144 .so option c is correct I.e 80
• 7 years agoHelpfull: Yes(6) No(0)
• 80% of 80 is 64.
  80+64=144
• 10 years agoHelpfull: Yes(5) No(2)
• let,
  CP = x Rs.
  
  Percentage-profit = x %,
  SO,
  selling-price = x + x*x/100 = 144,
  OR,
  x^2 +100x -14400 = 0, ==> (x-80)(x+180) = 0,
  x = 80, &, x = -180,
  Hence,
  Cost-Price = Rs. 80
• 10 years agoHelpfull: Yes(3) No(0)
• sp =144
  cp=144-x
  profit is x% (equal to cp)
  then
  sp=cp+profit%
  
  144-x=144*x/100
  144=(144x+100x)/100
  x=59.02
  means 144-60=80 ans
  
• 9 years agoHelpfull: Yes(1) No(1)
• x^2 +100x -14400 = 0, => (x-80)(x+180) = 0,
  x = 80, &, x = -180,
  Hence,
  Cost-Price = Rs. 80
• 9 years agoHelpfull: Yes(1) No(0)
• my answer would be 80.
  
  solution
  
  let x be the cost price. so the profit percent is x too
  
  Selling price = x + (x*x)/100
  144 = x+ x*x/100
  
  x2+100x-14400 =0
  x =-180 or x= 80
  
  So CP =80.
• 9 years agoHelpfull: Yes(0) No(0)
• 80 it satisfies the given condition
• 6 years agoHelpfull: Yes(0) No(0)