Bunuel
A right circular cylinder-shaped coin made of an aluminum-silver alloy weighs 30 grams and has a diameter of 15 mm and a height of 2 mm. The coin contains equal volumes of aluminum and silver, with silver being twice as heavy as aluminum. What is the weight of a pure aluminum circular cylinder-shaped coin with a diameter of 30 mm and a height of 1 mm?
A. 36 grams
B. 40 grams
C. 42 grams
D. 48 grams
E. 80 grams
I have done this problem using mixture table. Please can any expert (@bunuel) weigh in and let me know if this approach is accurate?
From the first coin - ALUMINIUM is 10g/30g = 33% (For easier calculation I would approximate it to 30%)
From the second coin- ALUMINIUM is 100% as the second coin is pure aluminum.
We also know the total weight of the first coin = 30g.
I would assume for a moment that I am combining the two coins to get a "mean value" and will then end up using that mean value to find the weight of the coin.
1st coin..........2nd coin
30%..............
100%.........
70%(mean value)...........
30.................
(70-30=40)All the values in pink are the information provided by the question. The mean value in blue can be found by subtracting 30 from 100. The value in green is the answer we have found out. Hence, the weight of the 2nd coin will be 40%.