5 1/8 8 goes into 41 5 times with 1 left over
Evan is not correct. While 25 is 125% of 20, it was <em>not</em> 125% more. That would be adding on to the 100% already there, for a total of 225%. It's actually only 25% more because of this.
Rate for Sally is 1 room per 8hrs
rate for Steve is 1 room per 7hrs
combined rate:
1/8 + 1/7 = 1/T
7/56 + 8/56 = 1/T
15/56 = 1/T
56/15 = T
3 11/15 = 3 hrs 44 min