Question

A golden wedding ring is 20mm in diameter and has a 14mm hole in the middle
A. What is the area of the ring
B. What is the cost of the ring if 1mmsquare of gold is equivalent to 5gh

Answer 1

Area = pi r^2 r = d/2

A. pi (10^2 - 7^2) = ?

B. Need volume rather than area. What is the thickness of the ring?

Answer 2

B. Assuming standardized ring pricing, as indicated by the price of 5gh/mm^2, then the cost is 5*(A) from above