1. 10 5/18 - 8 5/6 =
a. 2 5/6
b. 2 13/18
c. 1 4/9
d. 1 11/18
2. 1 2/5 ÷ 2 1/3
a. 1 1/12
b 1 1/5
c. 3/5
d. 3 4/15

< coa = 150 ( given)

as ba and bc are tangents

so oc and oa is perpendicular to cb and ab respectively because in circle normal passes through centre

so in quadrilateral oabc

< coa + < oab + < ocb + < abc = 360

150 +90+90 + < abc = 360

330 + < abc = 360

< abc = 360 -330 = 30

so < abc = 30

⭐dhruv⭐