$\tiny{231.13.3.75}$
$\textsf{Imagine $3$ unit spheres (radius equal to 1) }$
$\textsf{with centers at, $o(0,0,0)$, $p(\sqrt{3},-1,0)$ and $q(\sqrt{3},1,0)$.} \\$
$\textsf{Now place another unit sphere symmetrically on top of these spheres with its center at R.} \\$
$\textsf{a Find the center...