There are three grades in the school. One grade has 1/3 of the students, one grade has 1/4 of the students. What fraction of students is in the remaining grade?

Step-by-step explanation:

Let x represent the total number of stdents that has all grades in the school.

There are three grades in the school. One grade has 1/3 of the students, this means that number of students that belongs tho this grade is 1/3 * x = x/3

One grade has 1/4 of the students, this means that number of students that belongs to this grade is 1/4 * x = x/4

Total number of students in both grades would be x/3 + / x/4 = 7x/12

The number of students in the remaining grade would be

x - 7x/12 = 5x/12

fraction of students in the remaining grade would be

(5x/12) / x = 5/12