Question 1069613
 A truck radiator is filled with 18 gallons of antifreeze solution.
 the concentration of glycol in antifreeze is 15%.
 how much of the solution should be drained and replaced with pure water so that the new solution is 10% glycol
:
let x = the amt of solution removed and the amt of water added to replace it
.15(18-x) = .10(18)
2.7 - .15x  = 1.8
-.15x = 1.8 - 2.7
-.15x = -0.9
x = -.9/-.15
x = +6 gallon of solution removed and 6 gallons of water added