Question 1173582:  Monica is 4 years older her brother Kevin. Kevin is 9 years younger than Robert, the oldest child in the family. The sum of their ages is 37. How old are Robert, Monica, and Kevin 
 Found 3 solutions by  ikleyn, josgarithmetic, MathTherapy: Answer by ikleyn(52903)      (Show Source): 
You can  put this solution on YOUR website! . 
    Robert + Kevin + Monica    = 37
      x    + (x-9) + ((x-9)+4) = 37
      x    +  x-9  +   x-5     = 37
          3x   -  14           = 37
          3x                   = 37 + 14 = 51
           x                             = 51/3 = 17.
ANSWER.  Robert is 17 years old;  Kevin is  17-9 = 8 years old;  Monica is 8+4 = 12 years old.
 
Solved.
 
 
 
 
 Answer by josgarithmetic(39630)      (Show Source):  Answer by MathTherapy(10557)      (Show Source): 
You can  put this solution on YOUR website!  
Monica is 4 years older her brother Kevin. Kevin is 9 years younger than Robert, the oldest child in the family. The sum of their ages is 37. How old are Robert, Monica, and Kevin 
Let Kevin's age be K 
Then Monica's is: K + 4, and Robert's is: K + 9 
We then get: K + K + 4 + K + 9 = 37 
3K = 24 
Kevin, or   
Now you should be able to find Monica's and Robert's ages.  
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