Grow up Fast

Answer: 59


Using the number of years that have passed

	Julie	Megan	Zoey
today	32	4	1
in $n$ years	32 + $n$	4 + $n$	1 + $n$

32 + $n$ = 4 + $n$ + 1 + $n$
            = 5 + 2$n$
27 = $n$

In 27 years Julie will be 32 + 27 = 59


Using algebra and Julie's age
Julie's age is $J$

$32-4=28$ so Megan's age is $J-28$
$32-1=31$ so Zoey's age is $J-31$
$$\begin{align}(J-28)+(J-31)&=J\\
\Rightarrow 2J-59&=J\\
\Rightarrow J&=59\end{align}$$ So Julie will be $59$.


Using trial

Julie	Megan	Zoey	M + Z
32	4	1
42	14	11	25	too small
52	24	21	45	too small
62	34	31	65	too big
61	33	30	63	too big
59	31	28	59	perfect

Julie is 59