<PRE><B>Question 974047</B>
Let the years ago be X

At X years ago Mommy grace will be (27-X)
At X years ago the son will be (13-X)

Note that according to the question, at X years ago age of mommy grace = 3 times age of son

Therefore (27-X) = 3 * (13-X)

27-X = 39-3X

3X-X = 39-27
2X = 12

X= 12/2
X= 6 years ago

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