In a classroom, 20% of students scored a perfect score of 100. If there are 30 students, how many scored 100?

To determine how many students scored a perfect score of 100, we begin by calculating 20% of the total number of students.

Given that there are 30 students in total, we can express 20% as a fraction:

[

20% = \frac{20}{100} = 0.2

]

Now, we multiply this percentage by the total number of students:

[

0.2 \times 30 = 6

]

Thus, 6 students scored a perfect score of 100.

This calculation shows that the correct answer is 6, but it's worth noting that 10 is the answer given by the student, which would represent 33.3% of the students instead of 20%, and does not match the conditions provided.