Step-by-step explanation:
1) butter = 9/10
sugar = 1/5 =2/10
butter - sugar = 9/10 - 2/10 = 7/10 =0.7 = 70%
2)
Jan = 1/2
Feb = 5/12
total = 1/2 + 5/12 = 6/12 + 5/12 = 11/12
3)
queen's ring = 1/2 = 2/4
princess's ring = 1/4
queen's ring - princess's ring = 2/4 - 1/4 = 1/4
4)same with 3)
5)
mon = 5/12
tues = 1/2 = 6/12
total = 5/12 + 6/12 = 11/12