Here is my answer.. correct me if im wrong.
6:30
- :20
----------
6:10
- :15
---------
5:55
- 1:
----------
4:55
- :45
--------
4:10 was when he started history
The hight of the step is
h ≥ 8 inches
If we take that in one feet we have twelve inches
The hight between floors are H=10ft = 120 inches
If we named number of steps with n, the appropriate inequality is
n ≤ 120/8 => n ≤ 15
Good luck!!!!
1375, separate the figure into two separate rectangles then add it up