Respuesta :

Answer:

4 questions

Step-by-step explanation:

20= 100%

20 times 5 =100

100-80=20

peter got 20% of the test wrong.

i will say he missed 4 questions because you still have to multiply it by 5

4 times 5=20

or you could also do this

20-4= 16

16 times 5= 80

so, peter   missed 4 questions