Length: 114 in.
Width: 132 in.
For length, you have 9 feet and 6 inches. Meaning that if you would want to get the length of his room in inches, you would have to multiply 9 with 12 and add 6.
It's the same thing for the width.
If you need more help comment below!
The empirical probability of a 4 or 5 is
(count of outcome = 4 or 5)/(count of all outcomes) = (44 +40)/240 = 7/20
The problem statement asks you to assume the outcomes will remain in this proportion going forward. That is, the number of outcomes (n) of 4 or 5 in the next 60 rolls of the number cube is expected to satisfy
7/20 = n/60
Multiplying that by 60 gives
n = 60*(7/20) = 21
Selection D is appropriate.