GreenlightTestPrep wrote:
Presently, Fred is 4 times as old as Gary. In 10 years, Fred will be 3 times as old as Gary. How old (in years) will Fred be in 3 years?
Let's solve the question using 2 variables
Let F = Fred's PRESENT age
Let G = Gary's PRESENT age
Presently, Fred is 4 times as old as GaryIn other words,
F = 4GIn 10 years, Fred will be 3 times as old as Gary.IN 10 YEARS, Fred's age = F + 10
IN 10 YEARS, Gary's age = G + 10
If Fred will be 3 times as old as Gary, we can write: F + 10 = 3(G + 10)
Expand: F + 10 = 3G + 30
Rearrange to get:
F = 3G + 20We now have the following system:
F = 4GF = 3G + 20Since both equations set equal to F, we can write: 4G = 3G + 20
When we solve this, we get G = 20
Since
F = 4G, we can now say that F = 4(20) = 80
In other words, Fred's PRESENT age is 80
So, IN 3 YEARS, Fred's age will be 83
Answer: 83
Cheers,
Brent
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Brent Hanneson - founder of Greenlight Test PrepSign up for our GRE Question of the Day emails