(b) Let p, q and r be three propositions defined as follows: p means 'Sofia is happy', q means 'Sofia paints a picture whereas r means 'Samir is happy' Express each of the three following compound propositions symbolically by using p,q and r, and appropriate logical symbols. i. 'lf Sofia is happy and paints a picture then Samir isn't happy ii. 'Sofia is happy only if she paints a picture' iii. 'Sofia either paints a picture or she is not happy