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