$\text{ Let }f\left(x\right)=\left[2x^3-5\right].\text{ Then, number of points of discontinuity of }f\left(x\right)\text{ in }(1,2)$

$f\left(x\right)=2x^3-5\text{ is an increasing function of }x\text{ on }(1,2)\text{ and }$

$f\left(1\right)=-3,f\left(2\right)=11\text{. Between }-3\text{ and }11\text{ there are thirteen points where }f\left(x\right)\text{ is }$$\text{ discontinuous. }$