Answer:
(a) How many grams of copper are in the resulting mixture?
= 160 grams
(b) What percentage of the resulting mixture is copper?
= 61.5%
Step-by-step explanation:
(a) How many grams of copper are in the resulting mixture?
From the question: Suppose that a certain alloy is made by mixing 70 grams of an alloy that contains 12% copper with 90 grams of pure copper.
The number of grams of copper in the resulting mixture = 70 grams + 90 grams = 160 grams
(b) What percentage of the resulting mixture is copper?
70 grams of an alloy that contains 12% copper = 70 × 12%
= 70 grams × 0.12
= 8.4 grams
The number of grams of copper in the resulting mixture = 160 grams
The percentage of the resulting mixture that is copper is
=( 8.4 grams + 90 grams of pure copper/160) × 100
= 98.4/160 × 100
= 61.5%
