Question

A chef is going to use a mixture of two brands of Italian dressing. The first brand contains 9% vinegar, and the second brand contains 14% vinegar. The chefwants to make 320 milliliters of a dressing that is 11% vinegar. How much of each brand should she use?

Answer 1

Let

x ------> milliliters first brand at 9%

y ------> milliliters second brand at 14%

so

we have that

x+y=320 ------> x=320-y ------> equation A

9%=0.09

14%=0.14

11%=0.11

0.09x+0.14y=0.11(320) ------> equation B

Solve the system of equations

substitute equation A in equation B

0.09(320-y)+0.14y=0.11(320)

solve for x

28.8-0.09y+0.14y=35.2

0.05y=35.2-28.8

0.05y=6.4

y=128

Find out the value of x

x=320-y

x=320-128=192

therefore

milliliters first brand at 9% is 192

milliliters second brand at 14% is 128