Three Identical Units of Merchandise Were Purchased During July,as Follows

Three identical units of merchandise were purchased during July,as follows:
$\begin{array}{|c|c|c|r|}\hline {\text { Date }} & \text { Product Basic H } & \text { Units } & \text { Cost } \\ \hline \text { July } 3 & \text { Purchase } & 1 & \$ 35 \\ \hline 10 & \text { Purchase } & 1 & 36 \\ \hline 24& \text { Purchase } & \underline{1} & \underline { 37 }\\ \hline & \text { Total } & \underline{3} & \underline { \$ 108 }\\\hline\\\hline & \text { Average cost per unit }&&\underline { \$36 } \\\hline \end{array}$
Assume one unit sells on July 28 for $45.
Determine the gross profit,cost of merchandise sold,and ending inventory on July 31 using a first-in,first-out,b last-in,first-out,and c average cost flow methods.