if you cut your widest measurement first---such as 12" wide strip---then from that cut your smaller measurement (like 2") you will find it easier to figure out-
remember you need to remove salvages so, you will not have 44" of usable fabric.
so- 70 pieces that are 2" X 3 1/2" you would start with cutting 3 1/2" strips- you can then cut (20- 21) 2" cuts from each strip- you need 70...so 3 strips gives you 60-63, cut a 4th strip in half if you want for 7-10 more pieces.
70 @ 5 1/2" you do the same way- cut your strips 5 1/2" wide (if you start with the widest needed then you can use 1/2 of the 4th strip for your extra (10) 5 1/2" pieces and the other half of it for the 3 1/2" pieces
and the 28 12" x 2" you would cut 2 strips 12"...(20) 2" pieces from one---you only need 8 from the second strip---again you could use the other half of the strip to cut some of the smaller pieces if you start with the widest strips needed & work your way down....good way to (stretch) your fabric. always start with the largest pieces you need & work your way down