Yoko Trucks Ltd. had the following data (in millions of yen) for a given period:

Sales ................................................................................¥770
Direct materials ...............................................................290
Direct labour ....................................................................140
Variable factory overhead ................................................60
Variable selling and administrative expenses .............100
Fixed factory overhead ...................................................120
Fixed selling and administrative expenses ....................45

There were no beginning or ending inventories. Compute (1) variable manufacturing cost of goods sold, (2) contribution margin, and (3) operating income.