Mixture question # 3

Question

Of 12 pounds of salt water 10% is salt; of another mixture 3% is salt. How

many pounds of the second should be added to the first in order to get a

mixture of 5% salt?

Answer 1

0.10(12) + 0.03x = 0.05(12 + x)

Can you solve for x and answer?

The solution is an example of the standard mixture equation.

Answer 2

Let us think. Two variables, total weight=x, and salt weight (from % salt)=y

going to need two equations.

1st equation.

.03=(y-1.2)/(x-12) have point (1.2,12) on plane, slope of added mixture is .03 pound salt/pound total

2nd equation.a

.05=y/x...y=.05x a line through origin representing .05 salt/total pounds

.03(x-12)=.05x-1.2

.02x=.84

x=42 pounds, but only 42-12=30 pounds is added.

answer 30 pounds.

check--

30(.03)+12(.10)=2.1

2.1/42=.05