Given :
An alloy is a mixture of metals. Suppose that a certain alloy is made by mixing 50 g of an alloy containing 12% copper with 78 g of an alloy containing 92% copper.
To Find :
How many grams of copper are in the resulting mixture what percentage of the resulting mixture is copper.
Solution :
Mass of copper in 50 gm alloy =
.
Mass of copper in 78 gm alloy =
.
Total mass of copper, ( 6 + 76.44 ) gm = 82.44 gram.
Percentage of copper in resulting mixture :

Hence, this is the required solution.
the problem with this study is the fact that they used precise numbers
hope i helped:)
Cosine = adjacent / hypotenuse
cos (49)= x/27
27 * cos(49) = x
27 * 0.656 = x
x = 17.7