Quiz

I think that the following version of question illustrates more precisely the problem.
You are giving a test which is time controlled and the question
"Express the value of 0,00005km in cm or in m, give the unit."
is the last one.
You are grading the question as 100% for the numerical value and you apply a penalty of 20% if the unit is not the correct one or badly written or not given.
Student - response

A 5 cm
B 5 m
C 0,05 m
D 0,05 cm
E 5 c
F 0,05
E 5
To which student(s) will you give a 100% grade, a 80% grade, a 0% grade ?
Pierre