Given data:
* The speed of the bus is 10 mph.
* The speed of the person in the bus is 2 mph.
Solution:
As the lecture hall is in state of rest with respect to Bus,
Thus, the speed of the person walking inside the bus with respect to the lecture hall is,
![\begin{gathered} S=\text{speed of bus+spe}ed\text{ during walk} \\ S=10\text{ mph + 2 mph} \\ S=12\text{ mph} \end{gathered}](https://img.qammunity.org/2023/formulas/physics/college/zajp0z5ulcamqwfgs3999mc9g2qt4l5er3.png)
Thus, the speed relative to the lecture hall is 12 mph.