please do part A and B and show work!

4. Eighty units of end item E are needed at the beginning of week 6 . Three cases ( 30 units per case) of J have been ordered and one case is scheduled to arrive in week 3 , one in week 4 , and one in week 5. Note. J must be ordered by the case, and B must be produced in multiples of 120 units. There are 60 units of B and 20 units of J now on hand. Lead times are two weeks each for E and B, and one week for J. a. Prepare a material requirements plan for component J. b. Suppose that in week 4 the quantity of E needed is changed from 80 to 70 . The planned-order releases through week 3 have all been executed. How many more Bs and Js will be on hand in week 6