You will have to be more specific as to what your problems are – there is no point in me simply typing the answer here when it is already in the Course Notes.
Part (a) simply needs to you to calculate the full profit per unit. Part (b) wants you to calculate how many to produce of each using a marginal costing approach (i.e. normal key factor analysis) Part (c) wants to you repeat part (b) but using a throughput accounting approach.
(If you have not yet watched the free lecture on key factor analysis/throughput accounting, then do so)