Help with Math Problem!?

Question

Mr.Jim has 40% & a 10% solution of plant food.He wants to make 10 Liters of a 20% food plant mixture.How many liters of each kind does he need?

Answer 1

Let x=liters of 40% plant food

0.4x+0.1(10-x)=10*0.2

solve for x...does this help?

Answer 2

Here's an explanation:

Let L = liters of 40% solution

And we know that 10 - L is how many liters of the 10% solution he needs.

So you can say:

40(L) + 10(10-L) = 20(10)

40L + 100 - 10L = 200

30L = 100

L = 3 1/3

So he used 3 1/3 liters of 40% solution and 10 - 3 1/3, or 6 2/3 liters of 10% solution.