if the number of 2 rs, 5 rs and 10 rs coins are 500 and total sum of money is 3130.when the 5 rs and 10 rs coins are exchanged .total sum is decreased by 300.what are the no of coin of 2 rs .

option a 200 b 210 c 140

• Ans is c.140
  let number of coins of 2 rps are x.
  Number of coins of 5 rps are y.
  No.of coins of 10 rps are x.
  Then
  x+y+z=500-----------(1)
  2x+5y+10z=3130----------(2)
  2x+10y+5z=2830-----------(3)
  solve (1),(2),and (3) you will get answer
  140 coins of 2 rps
  150 coins of 5 rps
  210 of 10 rps coins
• 10 years agoHelpfull: Yes(25) No(0)
• By using given options
  140*2=280
  so remaining coins are 500-140=360
  given that if 5rs and 10rs coins are exchanged total sum decreases by 300
  so the difference between 10rs and 5rs coins is 60(300/5)
  now divide 360 in a way that difference between two numbers is 60
  i.e, 210,150
  
  210*10=2100
  150*5=750
  140*2=280
  
  2100+750+280=3130
  
  so ans is c)140
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• x+y+z=500-----------(1)
  2x+5y+10z=3130----------(2)
  2x+10y+5z=2830-----------(3)
  
  so number of Rs2 = 140
• 10 years agoHelpfull: Yes(0) No(0)
• c=140 where y=150,z=210,
  3 eq are there
  x+y+z=500
  2x+5y+10z=3130
  2x+5z+10y=2130
  put x=500-y-z
  and solve accordingly
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• ans s c-140
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