The ratio of the present ages of a man and his wife is 4 : 3. Which of the following can't be a possible ratio of their ages 30 years ago?  Choose one:
A) 2: 4  B) 3: 4  C) 4:4  D) 5: 4  E) 6: 4
4x-30/3x-30 = 5/4   Therefore x=-30   Age cannot be negative.   Answer: 5: 4
<result>D</result>
The ratio of the present ages of a man and his wife is 4 : 3. Which of the following can't be a possible ratio of their ages 30 years ago?