24:15 would be the simplified version, if that's what you meant.
3/4 = x / 340....3 to 4 students = x to 340 students
cross multiply
(4)(x) = (3)(340)
4x = 1020
x = 1020/4
x = 255 <==
or this way.....
3 out of 4 students.....3/4 = 75%
so 75% of 340 = 0.75(340) = 255 <=
X is the ounces
Got this answer because you figured it out