$10\mathrm{.}11$ A consolidated drained triaxial test was carried out on a normally consolidated clay specimen with confining pressure of $75\mathrm{.}0k\frac{N}{m^2}.$ The deviator stress at failure was $96\mathrm{.}0k\frac{N}{m^2}.$ An identical specimen of the same clay was subjected to a consolidated undrained triaxial test, where the confining pressure is $150\mathrm{.}0k\frac{N}{m^2}.$ The deviator stress at failure was $115\mathrm{.}0k\frac{N}{m^2}.$ What would be the pore water pressure at failure?