Question 1130579
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Very badly worded problem; and, exactly as stated, it is nonsense.<br>
"In eight years, the sum of their ages will be three-fifths as old as her mother at that time."<br>
(1) "the sum of their ages will be three-fifths as old as..." says that the sum has an age.  But a sum is a number; it doesn't have an age.  The sum of the two ages can't be "3/5 as old as" one of the ages.<br>
(2) If the sum of two ages is 3/5 of one of the two ages, then the second age is a negative number -- which is clearly nonsense.