college algebra

Question

solving a percent mixture problem using a system of linear equations

a scientist mixes water (containing no salt) with a solution that contains 35% salt. she wants to obtain 210 ounces of a mixture that is 5% salt. how many ounces of water and how many ounces of the 35% salt solution should she use?

Answer 1

.35x + .00(210-x) = .05(210)

.35x = 10.5

x = 10.5/.35 = 1050/35 = 210/7 = 30 ounces of 35%

210-30 = 180

mixed with 180 ounces of water yield 210 ounces of 5%

0 is within 5 of 5

35 is within 30 of 5

you need 30/5 or 6 times as much water. 180/30 = 6