Problema Solution
Seven years ago,scott was 3 times as old as Cathy was at that time.If Scott is now 5 years older than Cathy, how old is Scott?
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Solution: Let S be Scotts age and K be Kathys age. Then translating the sentence If Scott is now 5 years older than Kathy, how old is Scott into an equation yields
S = K + 5
Now, Scotts age 7 years ago can be represented as S = -7, and Kathys age can be represented as K = -7. Then translating the sentence Seven years ago, Scott was 3 times as old as Kathy was at that time into an equation yields
S - 7 = 3(K - 7)
Combining this equation with S = K + 5 yields the system:
S - 7 = 3(K - 7)
S = K + 5
Solving this system gives 14 1/2.