Answer :
- Let no of questions be x
- For each correct answer she earns 3 points
So let's find
[tex]\\ \tt\hookrightarrow 75+3x>90[/tex]
[tex]\\ \tt\hookrightarrow 3x>15[/tex]
[tex]\\ \tt\hookrightarrow x>15/3[/tex]
[tex]\\ \tt\hookrightarrow x>5[/tex]
Answer is 6