Linear Equation type of question (fuel mixture)

usman77

New member
Joined
Feb 22, 2006
Messages
5
here is the question:

Premium gasoline sells for 78.9cents/Liters. Regular gas sells for 71.9 cents/ litres. To boost sales, a middle octane gasoline is formed by mixing premium and regular. If 1000 L of this middle octane gas is produced, and is sold at 73.9 cents/Litres, then how much of each type of gasoline can you assume was used in the mixture?

Answer : 600 L premium and 400 L regular.........i got the answer from the back of the buk.....but i m not able to solve this question and get this answer

help plz :(
 
let x = amount of premium gas in liters
1000 - x = amount of regular gas in liters

x(.789) + (1000-x)(.719) = 1000(.739)

solve for x to determine the number of liters of premium

after you find x, 1000 - x will tell you the number of liters of regular

go for it.
 
That's exactly what I came up with, skeeter. The answer is not 600 and 400. I thought maybe I was doing something wrong.
 
Mr U.S. Man, them thingies all work this way:
Code:
  a   @ x
  b   @ y
=========
(a+b) @ z
z = (ax + by) / (a + b)
 
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