Correct Answer - Option 2 : 15.78
Calculation:
Let K and P are amounts of alloys used in the preparation of the new alloy.
⇒ Amount of Zinc in the new alloy = (K/4) + (3P/5)
⇒ Amount of Aluminum in the new alloy = 2P/5
⇒ Amount of Carbon in the new alloy = 3K/4
In the new alloy, the Amount of Aluminum and Zinc are in the ratio 3 : 5.
⇒ (2P/5)/((K/4) + (3P/5)) = 3/5
⇒ 2P = (3K/4) + (9P/5)
⇒ P/5 = 3K/4
⇒ P = 15K/4 or K = 4P/15
Percentage of Carbon in the new alloy = ((3K/4)/(K + P)) × 100
⇒ ((3K/4)/(19K/4)) × 100 = 15.78 %
In these types of problems, it is important to find the relation between the quantity of the solutions used for the preparation of the new solution.
If the quantity of the solutions used for the preparation for the new solution is equal, then we can calculate the volume of a component by simply taking the average of their ratios in the old mixtures.
For example: The amount of Zinc in the new alloy = ((1/4) + (3/5))/2 = 17/40