22. In a survey of 26 instructors, it was found that 11 liked whiteboards, 18 like blackboards, and 8 liked both. How many instructors like whiteboards only? How many instructors liked blackboards only? How many instructors liked neither?

a) 3

b) 10

c) 5                                

Step-by-step explanation:

We are given the following in the question:

Sample size, n = 26

Instructor that like whiteboards = 11

Instructor that like blackboards = 18

Instructor that like both boards = 8

We have to find the following:

a)  instructors like whiteboards only

b)  instructors liked blackboards only

c)  instructors liked neither

< 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⭐

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step-by-step explanation: