What is the simplest formula of a compound containing 50% of element A (atomic weight = 10) and 50% of element B (atomic weight = 20) ?

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What is the simplest formula of a compound containing 50% of element A (atomic weight = 10) and 50% of element B (atomic weight = 20) ?

A. AB3
B. A2B3
C. A2B
D. AB2