Two three$-$phase wye$-$connected loads are in parallel across a three$-$phase supply. The first load draws a phase current of $10$ A at $0\mathrm{.}95$ power factor leading, and the second load draws a phase current of $20$ A at $0\mathrm{.}75$ power factor lagging. Calculate the following:

$($a$)$ Real power supplied by the source if the supply phase voltage is $300$ V $.$

$($b$)$ Line current from the source side and its power factor.