TOLONG BANGET OK DIJAWAB DENGAN BENAR PLS!!!!!!!

15 : 30/7 =15 x 7/30 = 3.5 = 3 1/2(b)
2 1/2 : 3 1/3 : 5/6 = 5/2 : 10/3 : 5/6 = 5/2 x 3/10 x 6/5 = 9/10

17. b. 3 1/2
18. c. 9/10