please prove me with explanations

Exercise 1 PHGH manufacturing wants to estimate costs for each product they produce at its Sharjah plant. The plant produces three products at this plant, and runs two flexible assembly lines. Each assembly line can produce all three products. Required: a. Classify cach of the following costs as either direct or indirect for each product. b. Classify cach of the following costs as cither fixed or variable with respect to the number of units produced of each product. Indirect Fixed Variable Direct Product line Supervisor's salary Depreciation on the factory's truck Wages of cleaning personnel for the factory Plant manager's wages Metal used for the product