Question

A chef is going to use a mixture of two brands of Italian dressing. The first brand contains 5% vinegar, and the second brand contains 15% vinegar. The chefwants to make 200 milliliters of a dressing that is 13% vinegar. How much of each brand should she use?

Answer 1

F is the number of ml of the first brand

S is the number of ml of the second brand

The first equation is

`F+S=200`

and for the second equation

`0.05F+0.15S=.13(200)`

we will let by itself F of the first equation

`F=200-S`

We will substitute the value of F in the second equation

`0.05(200-S)+0.15S=.13(200)`

then we simplify the expression

`10-0.05S+0.15S=26`
`10+0.1S=26`

then we let by itself S

`S=(26-10)/(0.1)=160`

then we substitute the value of S in the equation with F isolate

`F=200-160=40`

Therefore

The chef will need 40 ml of the first brand and 160 ml of the second brand