Question:
John is twice as old as Mary. The sum of their ages is 21.
Last updated: 7/21/2022
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John is twice as old as Mary. The sum of their ages is 21. How old is Mary? Let J = John's age and M = Mary's age. Select the system equations that represents the problem. J-2M=0 J-M=2 M-2J=0 J+M=21