Answer:
60
Explanation:
If he had 313 balloons, and 13 of them popped, he would be left with 313-13=300 balloons. To determine how many balloons were in each room, you would divide 300 by 5 because he is dividing them evenly into 5 rooms. 300 divided by 5 is 60, so there were 60 balloons in each room.