All but 1/13 of the students enrolled at a particular elementary school participated in "family fun night" activities. if a total of 396 students were involved in the evening's activities, how many students attend the school?

429

Step-by-step explanation:

If all but 1/13 of the students were involved in the evening's activities, that means that 12/13 of the students were involved.

To calculate the total number of students, first you do a simple rule of three to know the number of students that weren't involved in the activities:

If 12/13 of the students represent 396 students, then how many students are 1/13 of the students?

Then, you add this number to the number of students that were involved in the activities:

So, 429 is the number of students that attend the school.

You can also calculate it directly by doing the following rule of three:

If 12/13 of students represent 396 students, then how many students are 13/13 of the students?

it is a. 4.2 because 7.6-3.4 gets the remaining length of 4.2. i might be wrong but i am pretty sure this is the answer.