Three pounds of 05 grass seed contain 1 percent herbicide. A different type of grass seed, 20, which contains 20 percent herbicide, will be mixed with three pounds of 05 grass seed. How much grass seed of type 20 should be added to the three pounds of 05 grass seed so that the mixture contains 15 percent herbicide? Choose the correct choice from the following choices.
A) 3
B) 3.75
C) 4.5
D) 8.4
E) 9
05 grass seed contains 5% herbicide and its amount is 3 pound   20 grass seed contains 20% herbicide and its amount is x   when these two types of grass seeds are mixed, their average becomes 15%   thus we have   3(1)+x(20)/(x+3) = 15   3+20x=15x +45   5x=42   or x=8.4   8.4
<result>D</result>
Three pounds of 05 grass seed contain 1 percent herbicide. A different type of grass seed, 20, which contains 20 percent herbicide, will be mixed with three pounds of 05 grass seed. How much grass seed of type 20 should be added to the three pounds of 05 grass seed so that the mixture contains 15 percent herbicide?