4. A solution of 60% fertilizer is to be mixed with a solution of 21% fertilizer to form 234 liters of a 43% solution. How many liters of the 60% solution must be used? SHOW YOUR WORK

Given:

A solution of 60% fertilizer is to be mixed with a solution of 21% fertilizer to form 234 liters of a 43% solution.

To find:

The quantity of the 60% solution in the mixture.

Solution:

Let x be the quantity of the 60% solution and y be the quantity of the 21% solution.

Quantity of mixture is 234. So,

                 ...(i)

The mixture has 43% fertilizer. So,

Multiply both sides by 100.

           ...(ii)

Using (i) and (ii), we get

Divide both sides by -39.

Putting this value in (i), we get

Therefore, 132 liters of the 60% solution must be used.