Question 1153474: Sandy was 25 years old when her son was born. Her present age is 7 years less than three times her son's present age. How old is Sandy now?
Let x = Sandy's age (the unknown under the question).
Then her son's age is (x-25) years.
From the condition,
x = 3*(x-25) - 7.
Hence,
x = 3x - 75 - 7
x = 3x - 82
82 = 3x - x
82 = 2x
x = = 41.
ANSWER. Sandy is 41 years old.