Answer
$0.059~ohm$
Work Step by Step
The differential form can be evaluated as follows:
$dR=\dfrac{\partial R}{\partial R_1} dR_1 + \dfrac{\partial R}{\partial R_2} dR_2+ \dfrac{\partial R}{\partial R_3} dR_3$
Re-write as:
$\triangle R=\dfrac{\partial R}{\partial R_1} \triangle R_1 + \dfrac{\partial R}{\partial R_2} \triangle R_2+ \dfrac{\partial R}{\partial R_3} \triangle R_3$
Plug in the given data, we have
$\triangle R=\dfrac{(11.7647)^2}{(25)^2} \times 0.125+ \dfrac{(11.7647)^2}{(40)^2} \times 0.2+ \dfrac{(11.7647)^2}{(50)^2} \times 0.25=138.408 \times (0.0002+0.000125+0.0001)$
Hence, we have $dR =\dfrac{1}{17} \approx~0.059 ohm$