The travels you have described are:
(Middle floor) + 8 + 5 - 9 + 7 - 32
= (middle floor) + 20 - 41
= (middle floor) - 21 brought her to floor #1.
So Middle floor - 21 = 1
Add 21 to each side: Middle floor = 22
The building has (2 x middle floor) = 44 floors.
The answer is 7.20 because $18 divided by 2.5% is 7.20
To get the reciprocal, simply flip the numerator and denominator. The reciprocal of 3/10 is 10/3.
