Susie is finishing a research project for her history class. on monday and tuesday she worked for 3 1/2 hours each day. on wednesday she worked for 2 3/5 hours. a)what was the total number of hours she worked on the project these 3 days? show your work. b)how many more hours did she work on the project on tuesday than she did on wednesday? show your work.

Ok 

If she worked 3 1/2 hours on Monday and Tuesday, 3 1/2 is the same as 3.5
so you do 3.5 × 2 = 7 hours

Then you need to add 2 3/5 hours to 7 hours which would add up to be 9 3/5 hours or 9.6 hours

So, she worked 9 3/5 hours in the 3 days

On Tuesday she worked 3.5 hours and on Wednesday she worked 2 3/5 hours (2 3/5 = 13/5 = 2.6 hours)

To find the difference subtract 2.6 from 3.5 
  3.5
-
   2.6

   0.9 hours difference

The answer for this question is 80