Problem $04\mathrm{.}018-$ Moment capacity of a unsymmetric I$-$beam with tension and compression stress limits

For the casting shown, determine the largest couple $M$ that can be applied without exceeding either of the following allowable stresses: ${}_{\text{a}\text{l}\text{l}}=+7$ksi,${}_{\text{a}\text{l}\text{l}}=-14$ksi.

The largest couple $M$ that can be applied without exceeding either of the following allowable stresses is $$

kip.in$.$