Please help me to solve this questions

Puan Osnita is the owner of Kinross Enterprise. The financial year end of the business is on 31 December annually. You are required to determine the Gross profits using: (a) the FIFO, (b) the LIFO and (c) the average methods The units of an item available for sale and purchase during the year were as follows: ii) Explain why the weighted average cost method's gross profits is more than the FIFO's method