Jawabanmu

2014-08-28T19:50:35+07:00
40 = (360/18) / (360/18 + 20/Mr) × 40,2
40 = 20 / (20 + 20/Mr) ×40,2
800 + 800/Mr = 804
800/Mr = 4
Mr = 800/4
Mr = 200