Given for the section shown in Figure,
M^{*} = 250 kNm,
f_{sy} = 500 MPa and
f_{c}^{′} = 25 MPa.
Compute A_{st} and (if necessary) A_{sc}. You may assume that each of A_{st} and A_{sc} can be accommodated in a single layer (by bundled bars as necessary). And that f may be taken as 0.8.