Compute the design strength, $M_n,$ for the ${10}^{\text{'}\text{'}}22\frac{1}{2}"$ beam of the example presented in class

for the following cases:

a$)f_c^{\text{'}}=6,000$;$f_y=60,000$

b$)f_c^{\text{'}}=3,000$;$f_y=80,000$

How much does the design flexural strength of the beam change with respect to that

computed in class? Is the minimum required net tensile strain satisfied? Discuss.