Question 1065354
When you "scale up" (or down) a shape,
to a similar shape where all dimension measurements
are changes by a factor {{{k}}} ,
the length ratio is {{{k}}} for all lengths,
the surface area ratio is {{{k^2}}} for al surfaces,
and the volume ratio is {{{k^3}}} for the one and only volume.
In this case,
{{{k^3=3375/1000=15^3/10^3=(15/10)^3}}} ,
so {{{k=15/10}}} and {{{k^2=(15/10)^2=15^2/10^2=225/100}}} .
Applying that factor to 250 square feet,
we find the size (in square feet) of the larger pool to be
{{{250*(225/100)=250*226/100=562.5}}}