At the entrance of the seventeen-storey building there are apartments from 1 to 68. On which floor is apartment 63.

1) Let’s calculate the number of apartments on one floor by dividing the total number of apartments in the entrance by the number of floors:
68: 17 = 4;
2) Find how many floors are under apartment 63. To do this, divide 63 by the number of apartments per floor and find the incomplete quotient of this division:
63: 4 = 15 (partial quotient) remainder 3;
3) Since there are 15 floors under apartment 63, it itself is located on:
15 + 1 = 16th floor;
Answer: apartment 63 is located on the 16th floor.