$3\mathrm{.}4$ The required flexural $($bending moment$)$ strength is of a reinforced concrete beam is $=260$kip $-ft$

Determine which of the following reinforcing bar arrangements

can be used for this beam.

a$)6-$#$6$

Material properties are:

b$)4-$#$8$

$f^{\text{'}}c=5$ksi

c$)3-$#$9$

fy $=60$ksi