Respuesta :
You need at least 42/60 correct, or 18/60 wrong.
[tex] \frac{x}{60} = 70\% \\ x = \frac{70}{100} \times 60 \\ x = 42[/tex]
[tex]60 - 42 = 18[/tex]
You can get 18 questions wrong.
Hope this helps and good luck on your test. - M