SOLUTION: Ben is 25 years younger than his father. His mother is 2 years younger than his father. Their total ages add up to 78 years how old is Ben?

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Question 956895: Ben is 25 years younger than his father. His mother is 2 years younger than his father. Their total ages add up to 78 years how old is Ben?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
(1) +b+=+f+-+25+
(2) +m+=+f+-+2+
(3) +b+%2B+f+%2B+m+=+78+
------------------------
Substitute (1) and (2) into (3)
(3) +f+-+25+%2B+f+%2B+f+-+2+=+78+
(3) +3f+-+27+=+78+
(3) +3f+=+105+
(3) +f+=+35+
and
(1) +b+=+f+-+25+
(1) +b+=+35+-+25+
(1) +b+=+10+
-------------------
Ben is 10
check:
(2) +m+=+f+-+2+
(2) +m+=+35+-+2+
(2) +m+=+33+
and
(3) +b+%2B+f+%2B+m+=+78+
(3) +10+%2B+35+%2B+33+=+78+
(3) +78+=+78+
OK