Question 1145715
Make a table
:
fat %  | gallons sol'n | percent fat | total gallons fat |
1% fat | x             | 0.01        | 0.01x             |
4% fat | y             | 0.04        | 0.04y             |
mixture| x + y = 5     | 0.02        | 0.02 * 5 = 0.10   |
:
Since x + y = 5, then x = 5 - y
:
Substitute for x in the table, then
:
0.01(5 - y) + 0.04y = 0.10
:
0.05 - 0.01y + 0.04y = 0.10
:
0.03y = 0.05
:
y = 0.05/0.03 = 1.6666667 is approximately 1.67 gallon
:
x = 5 - 1.67 = 3.33 gallons
:
3.33 gallons of 1% fat mixed with 1.67 gallons of 4% fat
: