SOLUTION: Mary is the younger than her sister Joan. The sum of their age is 15. Twice Joan’s age is three times the sum of 5 and Mary’s age. How old are the two sisters?
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-> SOLUTION: Mary is the younger than her sister Joan. The sum of their age is 15. Twice Joan’s age is three times the sum of 5 and Mary’s age. How old are the two sisters?
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Question 246126: Mary is the younger than her sister Joan. The sum of their age is 15. Twice Joan’s age is three times the sum of 5 and Mary’s age. How old are the two sisters? Answer by checkley77(12844) (Show Source):
You can put this solution on YOUR website! M+J=15 OR M=15-J
2J=3(M+5)
2J=3(15-J+5)
2J=3(20-J)
2J=60-3J
2J+3J=60
5J=60
J=60/5
J=12 ANS. JOAN'S AGE.
M=15-12
M=3 ANS. FOR MARY'S AGE.
PROOF:
2*12=3(3+5)
24=3*8
24=24
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