Question 441657
{{{35(1/240 + 1/x) = 1}}}
==> {{{1/240 + 1/x = 1/35}}}
==> {{{1/x = 1/35 - 1/240 = 41/1680}}}
==> {{{x = 1680/41 = 40&40/41}}} minutes for Ahmed to paint the entire wall by himself.