The query: My father was born in 1947. I was born in 1971. At what age was I when he was exactly twice my age?
I know the answer is 23.5 through deductive reasoning, but is there a formula that can be used to efficiently solve this?
Chris R and Matt, those are both perfect! I have to wait 4 hours to vote. I really appreciate it. Didn't realise it was that incredibly simple.
JB
Favorite Answer
Ignoring the issue of what month you were born in versus your father, I would solve it like this:
1971-1947 = 24, so he was 24 when you were born (i.e. 0). x years later he was 24 + x and you were x, so you need to solve the equation:
24 + x = 2x, which says his age is twice yours. Subtracting x from both sides gives 24=x, your age when he was twice your age.
To get it more accurately, you need to know the months, not just the years in which you were born. But you should be able to see, that all you have to figure out is your fathers exact age at the time of your birth, and that is the age you will be when he is twice your age.
sahsjing
Let x be the number of years after 1971 when father's age was 24.
24+x = 2x
x = 24 years
So, in 1995 my father's age (48) was double my age (24).
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Ideas: Pick the year "I" was born as the starting point.
Matt
Let x be his age and y be your age. Since you were born 24 years after him, we have x=y+24. For him to be twice as old as you, we need:
x = 2y
y+24 = 2y
y = 24
So you were 24 when he was twice your age (48). I hope that helped!
Chris R
just y2 - y1
y2 being your year of birth
y1 being your fathers year of birth
this will give you the answer to the nearest year.