well following the directions you have provided me I would say that Jen will have
3 Gallons of strawberries. Work: So the fraction 3/4 can be converted into decimals which is .75 and since she got that many in half and hour ( 30 minutes) we can do two set of .75 for each hour, after we do the math we end up with 4 sets in total of .75 since she had 2 hours to work.
Equation .75*4=3 I hope this helped you out!