Question $8(10$ points$)$

A two$-$span continuous beam has several load applied, resulting in the shear and moment diagram shown below.

A$.$ If the designer selects a $4^{\text{'}\text{'}}$ wide by ${10}^{\text{'}\text{'}}$ deep rectangular beam, what is the resulting maximum bending stress?

B$.$ If the allowable bending stress is limited to $2,500,$ what is the required depth of beam if the width remains $4"?$ Round up to the inch.