>Mary, who is sixteen years old, is four times as old as her

>>8955329
pls be trolling

Either its bait or op is a massive brainlet

24

>>8955361
how did you manage?

>>8955329
Empiriclese

>>8955329
[math]x=4[/math]
[math]4x=16[/math]
[math]4x+y=2(x+y)[/math]
[math]4x+y=2x+2y[/math]
[math]2x=y [/math]
[math]y=8[/math]
[math]4x+y=24[/math]

m = 16
k = 1/4
f = 2

[math] M(t) = m + t [/math]
[math] B(t) = k\,m + t [/math]

[math] m+T == f\,B(T) [/math]
[math] \implies T=m\,\dfrac{1-k\,f}{f-1} [/math]
[math] \implies M(T)=m\,(1-k)\dfrac{f}{f-1} [/math]

>>8955404
Explain what you did there.

>>8955404
lol

>>8955329
Literally 6th grade algebra.

>>8955404
You're a fag

>>8955565
This

It's literally just (16 + x)/(4+x) = 2

>>8955329
yes, 8 years down the line she will be only twice older than him, are you in middle school?

>>8955329

"16 = 4b"
so b = 4

"when will she be twice his age?
age diff = 12, so when the younger is 12, older = 12 + 12 = 2x age

ANSWER = 24