Which is the major product when 3-methylbutan-2-ol is heated with concentrated $\mathrm{H}{}_2\mathrm{SO}{}_4$ (Saytzeff product after rearrangement)?

The secondary cation is formed first, then a 1,2-hydride shift from the tertiary carbon gives the tertiary cation $(\mathrm{CH}{}_3){}_2\mathrm{C}{}^{+}\mathrm{CH}{}_2\mathrm{CH}{}_3$. Proton loss from the more substituted neighbour gives the trisubstituted 2-methylbut-2-ene as the major alkene.