Answer :
Heyy wothackeror!! Here's your answer:
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Given,
Marks for each correct answer = 3
Marks for each incorrect answer = -1
Marks Sona obtained = 20
Number of answers she got correct = 10
∴ Number of answers she got incorrect =
Let's take the incorrect answers as x.
[tex]∴ 10×3+x×(-1) = 20[/tex]
[tex]\rightarrow 30+(-x) =20[/tex]
[tex]\rightarrow 30-x = 20[/tex]
[tex]\rightarrow -x= 20-30[/tex]
[tex]\rightarrow -x= -10[/tex]
[tex]\rightarrow x = 10[/tex]