CFAI questions, Minority Interest 320, includes, interest, question

ramzes

For question #26, on reading 21, the answer states that Equity includes a 320$ non controlling interest. How did they obtain 320? The total equity of the target company is 580$, if you multiply that by thier percent stake (50%) it equals 290. I thought you calculate minority interest as the equity amount times the ownership that is held by outsiders.