Which sample is biased? A.
interviews of random teenagers who attended a rock concert to find out which musician teens enjoy most
B.
a poll randomly surveying half of the students in grade 7 to find out which seventh-grade teacher at the school is most liked
C.
an online survey by a game development company taken after the game closes to find out which features of a new game players liked the most
D.
a questionnaire delivered to two employees from every department of an office to find out whether employees like the new coffee machine

D

Step-by-step explanation:

sorry if im wrong, but first two say random and third one says its and online survey, so everyone takes it, but the fourth one just say "two employees" those could be anyone, from only fat people to people that dislike coffee.

< 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⭐

the answer would be 150 books

step-by-step explanation:

if you divide 300 by 2 you will get 150