A company has the following inventory data:

December $1$ Beginning inventory of $15$ units at $$6\mathrm{.}00$ per unit

December $7$ Purchased $60$ units at $$6\mathrm{.}60$ per unit

December $12$ Sold $35$ units

December $20$ Purchases $30$ units at $$7\mathrm{.}20$ per unit

December $29$ Sold $25$ units

Assuming that a perpetual inventory system is used, what is the ending inventory on a LIFO basis for December? What if a periodic inventory system had been used instead of perpetual?