The total resistance, $R$, of a particular group is given by the formula: $$R = S + \left(\frac{1}{\frac{1}{T}+\frac{1}{W}}\right)$$

This formula can be simplified to the form $\frac{A}{B}$ where $A$ and $B$ contain no fractions.
$A =$
$B =$


Suppose that $S = 15 \Omega$, $T = 63 \Omega$ and $W = 87 \Omega$.
Then $R =$ $\Omega$

Note: Your answer must be a decimal.