Answer :
Answer:
40 questions
[tex]correct \: questions = (100 - 22.5)\% \\ = 77.5\% \\ let \: total \: questions \: be \: x \\ = > 77.5\% \times x = 31 \\ \frac{77.5}{100} \times x = 31 \\ 77.5x = 3100 \\ x = 40 \\ = 40 \: questions[/tex]
Answer:
40 questions
[tex]correct \: questions = (100 - 22.5)\% \\ = 77.5\% \\ let \: total \: questions \: be \: x \\ = > 77.5\% \times x = 31 \\ \frac{77.5}{100} \times x = 31 \\ 77.5x = 3100 \\ x = 40 \\ = 40 \: questions[/tex]