An alchemist discovered that the formula expressing the correct proportions needed to turn ordinary metal into gold is G = 1/2M + 15, where G is the number of gold bars and M is the number of metal bars. If a metal bar weighs twice as much as a gold bar, how many metal bars will yield an equal weight of gold?  Select the correct option:
A) a.	A - 10	B) b.	B - 15	C) c.	C – 22.5	D) d.	D – 30	E) e.	E – 67.5
A --- 10/2 + 15 = 20 --- CORRECT   B --- 15/2 + 15 = not an integer --- wrong   C --- 22.5(1/2) + 15 = not an integer --- wrong   D --- 30/2+15 =30 --- wrong   This is one of those problems that will probably be easiest to solve by plugging in numbers. The algebra is do-able, but it's not worth the effort (in my opinion). I was able to solve it in under 30 seconds total with this method.   a.	A - 10
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An alchemist discovered that the formula expressing the correct proportions needed to turn ordinary metal into gold is G = 1/2M + 15, where G is the number of gold bars and M is the number of metal bars. If a metal bar weighs twice as much as a gold bar, how many metal bars will yield an equal weight of gold?