Suppose the elements X and Y combine to form two compounds XY₂ and X₃Y₂. When 0.1 mole of XY₂ weighs 10 g and 0.05 mole of X₃Y₂. weighs 9 g, the atomic weights of X and Y are
A. 20, 30
B. 30, 20
C. 40, 30
D. 60, 40
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