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| Question 1153411:  Joe's father is 4 times as old as joe.6 years from now, Joe's father will be 3 times as old as Joe. How old is each now?
 Answer by Theo(13342)
      (Show Source): 
You can put this solution on YOUR website! x = joes's age now. y = joes's father's age now.
 today, joes's father's age is 4 times joe's age.
 you get:
 y = 4x
 in 6 years, joe's father's age will be 3 times joe's age.
 you get:
 y + 6 = 3 * (x + 6)
 simplify to get:
 y + 6 = 3 * x + 18
 subtract 6 from both sides of he equation to get:
 y = 3x + 12
 you have two equations that need to be solved simultaneously.
 they are:
 y = 4x
 y = 3x + 12
 since y = 4x in the first equation, replace y with 4x in the second equation to get:
 4x = 3x + 12
 subtract 3x from both sides of the equation to get:
 x = 12
 that would be joe's age now.
 that makes joe's father's age 4 * 12 = 48 now.
 in 6 years, joe will be 12 + 6 = 18
 in 6 years, joe's father will be 48 + 6 = 54
 54 is equal to 3 * 18.
 requirement of the problem are satisfied.
 the solution is:
 joe is 12 years old and joe's father is 48 years old now.
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