Question 43382
{{{1/R = 1/A + 1/B}}}
or {{{1/R = (A + B)/(A*B)}}}
or {{{R = A*B/(A + B)}}}


So you are wrong!


You must note that {{{1/A + 1/B}}} and {{{1/(A + B)}}} are not the same. Here you committed the mistake.