I was born 30 years after my father. My sister was born 25 years after my mother. The average age of my family is 26.25 right now. My sister will get married 4 years from now and will leave the family. Then the average age of the family will be 107/3. Then what is the age of my father right now?

a)34
b)36
c)40
d)45

My answer is (c) 40 But It is wrong :(
Please solve it and show process......
THANKS IN ADVANCE

1
do u know the real ans.?
i think the ans is 45
yes the answer is 45.... but how?
check the sol.given

Answers

2015-03-21T10:13:42+05:30
let x and y be his and his sister's present age respectively.
then,his father's age=x+30, mom's age=y+25
[(x+30)+x+(25+y)+y]/4=26.25
55+2x+2y=105
2x+2y=50
x+y=25.............................(1)
after 4 years,
[(30+x+4)+x+4+(25+y+4)]/3=107/3
(67+2x+y)/3=107/3
67+2x+y=107
2x+y=40..........................(2)
from 1 and 2,we get,:
x+y-2x-y=25-40= -15
i.e. -x=-15
hence,x=15
thus, father's age= 15+30=45
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