Question 479078
{{{5(1/16 + 1/20) + A/16 = 1}}}

<==> {{{5/16 + 1/4 + A/16 = 1}}}

==> {{{(5+A)/16 = 3/4}}}

==> {{{(5+A)/4 = 3}}}

==> 5 + A = 12

==> A = 7 days for A to finish the remaining work.