Answer: 14.67 pounds of second alloy must be added to the first alloy to get 12% mixture.
Step-by-step explanation:
Since we have given that
A alloy of 14% tin weigh 22 pounds.
There is a second alloy of 9% tin .
we need to find the quantity of second alloy that must be added to first alloy get a 12% mixture.
We will use "Mixture Alligation":
Ist alloy IInd alloy
14% 9%
12%
-------------------------------------
12-9 : 14-12
3 : 2
Since Ist alloy = 22 pounds
According to question, it becomes,

Hence, 14.67 pounds of second alloy must be added to the first alloy to get 12% mixture.