I am getting confused after doing Mock 1. When should I use equity vs available-for-sale? It seems that as long as I have control over the invested company, then I have to use equity. If I want to use AFS/Trading method, does it have to be <20% ? Any genius around??? THANKS !!

If there’s no significant influence, go with cost/market. If there is significant influence (regardless of percentage) go with equity. It has less to do with numbers and more to do with the amount of influence you have.