How would I work the following problem?

Using a periodic system Mower-Blower Sales Co. started business on Jan 20, 2016. Products sold were snow blowers and lawn mowers. Each product sold for $1400. Purchased during 2016 were as follows

		Blowers		Mowers
21-Jan		20 x 800
3-Feb		40 x 780
28-Feb		30 x 760
13-Mar		20 x 760
6-Apr				20 x 840
22-May				40 x 860
3-Jun				40 x 880
20-Jun				60 x 920
15-Aug				20 x 860
20-Sep				20 x 840
7-Nov		20 x 800

The December 31, 2016, inventory included 10 blowers and 25 mowers.

Assume the company uses a periodic inventory system.

a. What will be the difference between ending inventory valuation at December 31, 2016, under the FIFO and LIFO cost flow assumptions? (Hint: Compute ending inventory under each method, and then compare results.)

b. If the cost of mowers had increased to $960 each by December 1, and if management had purchased 30 mowers at that time, which cost flow assumption was probably being used by the firm? Explain your answer.