<PRE><B>Question 516479</B>
Let
Present age of Ben = b
Present age of Joe = j


Ben is twice Joes age 
b=2j.......(1)

The sum of their ages equal 57 
b+j=57.......(2)

Put the value of b from (1) to (2)
2j+j=57
3j=57
3j/3=57/3
j=19
Put the value of j in (1)
b=2j
b=2*19
b=38

Joe is 19 and Ben is 38 years old.
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