SOLUTION: Four years ago, the father's age was three times the age of his son., The total of the ages of the father and the son after four years, will be 64 years. What is the father's age a

Algebra ->  Average -> SOLUTION: Four years ago, the father's age was three times the age of his son., The total of the ages of the father and the son after four years, will be 64 years. What is the father's age a      Log On


   



Question 1102620: Four years ago, the father's age was three times the age of his son., The total of the ages of the father and the son after four years, will be 64 years. What is the father's age at present ?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = the son's age now
Let +b+ = the father's age now
---------------------------------
(1) +b+-+4+=+3%2A%28+a+-+4+%29+
(2) +%28+a+%2B+4+%29+%2B+%28+b+%2B+4+%29+=+64+
--------------------------------
(1) +b+-+4+=+3a+-+12+
(1) +3a+-+b+=+8+
and
(2) +a+%2B+b+%2B+8+=+64+
(2) +a+%2B+b+=+56+
-------------------------
Add (1) and (2)
(1) +3a+-+b+=+8+
(2) +a+%2B+b+=+56+
----------------------
+4a+=+64+
+a+=+16+
and
(2) +16+%2B+b+=+56+
(2) +b+=+40+
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The father is 40 at present
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check:
(1) +b+-+4+=+3%2A%28+a+-+4+%29+
(1) +40+-+4+=+3%2A%28+16+-+4+%29+
(1) +36+=+3%2A12+
(1) +36+=+36+
and
(2) +%28+a+%2B+4+%29+%2B+%28+b+%2B+4+%29+=+64+
(2) +20+%2B+44+=+64+
(2) +64+=+64+
OK