Tolong Jawab ya. Ga ngerti . + caranya yak. please

6,95 ton =(20×35) + (25×20) + (30×25) + (50×n) + (100×30)
(6,95×1000kg) = 700 + 500 + 750 +50n + 3000
6950 = 4950 + 50n
6950 - 4950 = 50n
2000 = 50n
n = 2000/50
n = 40

jadi byk karung semuanya = 35+20+25+40+30
= 150