${{\Delta l} \over l} = 0.1$  $\therefore$ $l = 1.1$

but the area also decreases by 0.1.

mass = $\rho lA = V\rho$, $\ln l + \ln A = \ln$ mass.

$\therefore$ ${{\Delta l} \over l} + {{\Delta A} \over A} = 0 \Rightarrow {{\Delta l} \over l} = {{ - \Delta A} \over A}$

Length increases by 0.1, resistance increases, area decreases by 0.1, then also resistance will increase. Total increase in resistance is approximately 1.2 times, due to increase in length and decrease in area. But specific resistance does not change.