9514 1404 393
Answer:
D
Step-by-step explanation:
The wording "must be under 315" means you can immediately throw out any answer choice that has "> 315" or "more than" in it.
The total number of seats in the auditorium will be the sum of the number in the balcony and the number on the floor. On the floor, 15 rows of x seats will be 15x seats altogether. Then the fire safety requirements are ...
floor seats + balcony seats < 315
15x + 60 < 315 . . . . . . matches choice D
The solution is ...
x + 4 < 21 . . . . divide by 15
x < 17 . . . . . . . .subtract 4
The variable x stands for the number of seats in a row, so x < 17 means there must be fewer than 17 seats in each row.