The last one would be incorrect. We are looking for PART of whatever N is. Multiply by the whole number 25 is definitely not what we want to do.
Hope I helped!
The teacher would have to grade 322 problems
14 (problems) x 23 (students)
Answer: 322
5x/3=35
5x = 35*3=105
x= 105/5 = 21
double check 5 x 21 = 105
105/3 = 35
