A student bought some pens at 8 each and some pencils at 31.50 each. If the total number of pens and pencils purchased is 16 and their total cost is 50, how many pens
did he buy?
be
as his

Step-by-step explanation:

Letthenumberofpensbexand

numberofpencilsbey

then

x+y=16ory=16−x

andtheirvalue

8x+1.5y=50

8x+(

2

3

)(16−x)=50

8x+24−(

2

3

)x=50

8x−(

2

3

)x=50−24

(

2

13x

)=26∴x=4

theny=16−x=16−4=12

< 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⭐