Yes, she can use this inequality and it does matter since the number of cars that the inequality provides will need to be equal to or more than that number in order for all the students to be able to go. Therefore, if we apply the inequality it would give us the minimum number of cars needed (n) like so
12 + 3n > 28 ... subtract 12 on both sides
3n > 16 ... divide both sides by 3
n > 5 1/3
Since there can't be 1/3 of a car and the number of cars needed must be higher than 5 1/3 then we would need a total of 6 cars to take all of the children.
