$3.$In August $2022,$ Susan $($a sole trader$)$ gave a business asset to her son. The asset had been bought by Susan for $91,500$ in July $2005$ and enhanced in May $2006$ at a cost of $34,500.$ The asset's market value in August $2022$ was $215,000.$ Both Susan and her son elected that the gain should be held$-$over.

Required

a$.$ Compute the amount of the held$-$over gain.

b$.$ Explain how the situation would differ if Susan's son had paid her $150,000$ for the asset.