Question

A chemical company makes two brands of antifreeze. The first brand is 35% anti freeze, and the second brand is 85% pure antifreeze. In order to obtain 150 gallons of a mixture that contains 75% pure antifreeze, how many gallons of each brand of antifreeze must be used.

Answer 1

Answer: There are 30 gallons of anti freeze of  first brand and 120 gallons of anti freeze of second brand.

Step-by-step explanation:

Since we have given that

Percentage of anti freeze in first brand = 35%

Percentage of anti freeze in second brand = 85%

Percentage of anti freeze in mixture = 75%

Total number of gallons of mixture = 150 gallons

We will use " Mixture and Allegation":

 First brand         Second brand

      35%                      85%

                      75%

------------------------------------------------------------------

85%-75%         :            75%-35%

    10                :               40

     1                 :                 4

So, Number of gallons of anti freeze in first brand is given by

$\dfrac{1}{5}\times 150\\\\=30\ gallons$

Number of gallons of anti freeze in second brand is given by

$\dfrac{4}{5}\times 150\\\\=40\times 3\\\\=120\ gallons$

Hence, there are 30 gallons of anti freeze of  first brand and 120 gallons of anti freeze of second brand.