Question

John is twice as old as Mary. The sum of their ages is 52. How old is Mary?
If J = John's age and M = Mary's age, which system of equations could be used to solve the problem?
2J = M and J + M = 52
J = 2M and J + M = 52
J = 2M and JM = 52

Answer 1

sum of ages is 52
so its either first or second option (J + M) = 52)
J = 2 x M

so now you can choose the correct one

Answer 2

need further help?