Math question room cleaning

Question

It takes Sarah 9/10 hour to clean 3/8 of a room. She continues to clean the room at this rate. How long does it take Sarah to clean the entire room?

Answer 1

9/10 to 3/8 is the same ration as X/1=X

(9/10)/(3/8) = (9/10)(8/3) = (3/10)8 = 24/10 = 2.4 hours to do it all

9/10 hour for 3/8 means 27/10 for 9/8 and 18/10 for 6/8, It has to be between 27.7 and 1.8 hours, twice as close to 27.7 as to 1.8

2.7-2.4 = .3

2.4-1.8 =.6

.6 = twice .3

Answer is 2.4 hours = 2 2/5 hours = 2 hours and 24 minutes