Question

A radiator contains 15 quarts of fluid, 25% of which is antifreeze. How much fluid should be drained and replaced with pure antifreeze so that the new mixture is 40% antifreeze? (Round your answer to two decimal places.)

Answer 1

if x is amount drained, that x is also amount of antifreeze added
0.25(15-x) + x = 0.40(15)
x = 3