Question 770461
Starting from {{{D/d=Q+r/d}}}, multiplying through by d gives {{{highlight(D=Qd+r)}}}


Given information is {{{Q=15r}}}, {{{d=10r}}}, {{{Q=240}}}.
Find then 240=15r, and {{{highlight(r=16)}}}.
From that, d=10*r, d=10*16, {{{highlight(d=160)}}}.


That is enough to find D.
{{{D=Qd+r}}}
{{{D=240*160+16}}}
{{{D=38400+16}}}
{{{highlight(D=38416)}}}