Let the marks of the students in class 1 be

the average of these 12 marks is 90, so

which means

similarly, let

be the marks of the students in the second class,
so

which means

The 32 students averaged:
When solving the equation, you first have h- 9/5. So it would by x=(h - 9/5). But you are not done yet. you still have to divide it by R to get x. So the final equation is x=(h - 9/5) ÷ R
The remainder is 9........
Answer is: C
√11 ≈ 3.3661
Which the closest to your answers is 3.3
First do 104/4 which equals which equals 26
so you can drive 26miles on one gallon
then do 78/26 which equals 3
so you used 3 gallons of gas on trip 2