# I really do not get how this problem help?

An automobile engine can run on a mixture of gasoline and a substitute fuel. If gas costs \$3.35 per gallon and the substitute fuel costs \$2 per gallon, what percent of a mixture must be substitute fuel to bring the cost down to \$3.08 per gallon? Relevance

An automobile engine can run on a mixture of gasoline and a substitute fuel. If gas costs G = \$3.35 per gallon and the substitute fuel costs S = \$2 per gallon, what percent of a mixture must be substitute fuel to bring the cost down to Cavg = \$3.08 per gallon?

This is a weighted average problem, where Cavg = aG + bS = (1 - x)G + xS and a and b are the weights. So you solve for x, then you have 1 - x and the percentage of each fuel in the mixture.

Cavg = G - xG + xS = G + x(S - G); and (Cavg - G)/(S - G) = x. ANS you can do the math.

• Anonymous
1 month ago

WRONG FORUM. Go to Homework Help in the Education category.

• Your "car" problem is actually a math problem and should be relocated to the homework help section, not the Cars & Transportation section...