Question 1163045
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(1) The difference in their ages is, and always will be, 5 years.<br>
(2) When Jenny's age is 3/4 of Jessie's age, their ages will be 15 and 20.<br>
(3) Since that will be 9 years from now, their current ages are 15-9=6 and 20-9=11.<br>
ANSWER: Jenny is 6; Jessie is 11<br>
If you don't understand step (2), here are a couple of formal ways to see it.<br>
You can rewrite the fraction 3/4 as an equivalent fraction in which the denominator is 5 more than the numerator.  Since the current denominator 4 is 1 less than the numerator 3, multiply numerator and denominator by 5: 3/4 = 15/20<br>
More formally, when Jenny's age is 3/4 of Jessie's age, their ages can be represented as 3x and 4x.  The difference between their ages is 4x-3x = x.  But the difference in their ages is 5 years, so x = 5.  And that means when Jenny is  3/4 as old as Jessie their ages will be 3x=15 and 4x=20.  Then, as before, their current ages are 9 years less, making them 6 and 11.<br>