Complicated answer.............
Answer:
(A)129 Pounds
Step-by-step explanation:
Let x be the number of 23% zink alloy
Therefore:
Since the total result is 516 pounds
The number of pounds of 42% zink alloy =516-x pounds
We then have the resulting equation:
0.23x+0.42(516-x)=0.3725*516
0.23x+216.72-0.42x=192.21
Colect like terms
0.23x-0.42x=192.21-216.72
-0.19x=-24.51
Divide both sides by 129
x=129 pounds
Therefore, the number of pounds of 23% zink alloy that must be mixed is 129 pounds.
Psi stands for pounds per square-inch.
It is a measure of pressure, and is the equivalent pressure of putting one pound on a square-inch of area.
For example, someone weighing 180 pounds standing on his feet, with a footprint area of 72 square-inches would exert a pressure of 180 pounds/72 square inches = 2.5 pounds per square-inch, or 2.5 psi.
