I don't think they would have equal amounts at first since the numbers are different. This is what I did to find out how much $ each had at the first place:
Alex spend $5 a day x 7(days of the week)= $35 + $8 = $43 ( total $ Alex had at the beginning).
Jim spend $3 x 7 = $21 Since Jim left 4 times more than Alex which is $8 you multiply $8 x 4= $32+ $21= $53. That's what Jim had at first.
I hope I helped :)