Question 1088580: Mary is 5 times as old as her daughter Ann. 3 years ago she was 9 times as old as Ann. How old is Mary now? Answer by ikleyn(52788) (Show Source):
M = 5A, (1)
M-3 = 9*(A-3). (2)
Substitute the expression (1) for M into equation (2). You will get
5A - 3 = 9*(A-3).
Simplify and solve for A:
5A - 3 = 9A - 27,
27 - 3 = 9A - 5A,
24 = 4A ====> A = = 6.
Answer. Ann is 6 years old. Mary is 6*5 = 30 years old.
