Answer:
38.5 years old
Explanation:
Let us represent Mrs.Kelly's age with the parameter (k). It is given that her brother is (15) years younger than her, thus his age is (k - 15). It is given that the sum of their ages is (62). Therefore one can form an equation with the given information and solve for the unknown.
(Mrs.Kelly's age) + (Brother) = (62)
Substitute,
(k) + (k - 15) = 62
Simplify,
k + k - 15 = 62
2k - 15 = 62
Inverse operations,
2k - 15 = 62
2k = 77
k = 38.5