tolong ya..pakai cara..mks:)

#a
Unsur lain = 1 - 3/4 - 1/7 = 28/28 - 21/28 - 4/28 = 3/28

Beratnya:
Air = 3/4 x 200 = 150 g
Sirup = 1/7 x 200 = 28,58 g
Unsur lain = 3/28 x 200 = 21,42 g

#b
Air = 150 g x 3,5 = 525 g
Sirup = 28,58 g x 3,5 = 100,03 g
Unsur lain = 21,42 g x 3,5 = 74,97 g