a reduction in the price of petrol by 10% enables a motorist to buy 5 gallons more $180. find the original price of petrol.4$/gallon5$/gallon6$/gallon10$/gallon

1) 4$/gallon
2) 5$/gallon
3) 6$/gallon
4) 10$/gallon

• I think this is the way to solve it not really sure
  
  Let X be no of litres of petrol & n be the price per litre
  
  Eqn 1 : x*n = 180
  
  Eqn 2 : (x+5) * (0.9n) = 180
  
  Simplifying eqn 2
  
  0.9xn + 4.5n = 180
  
  Substituting eqn 1 in eqn 2
  
  0.9 ( 180) + 4.5n = 180
  
  n = 18/4.5 = 4
• 10 years agoHelpfull: Yes(0) No(0)