(a) The following information relates to Joplin Company for the period just ended: All of the company's overhead is variable or fixed in nature. Required: (i) Calculate the spending and efficiency variances for variable overhead. (5 marks) (ii) Calculate the expenditure and volume variances for fixed overhead. (5 marks) (iii) Provide possible explanations for the answers calculated in part (i) and (ii) above. (5 marks) (b) Standard costing can be a highly useful tool for managers. It can assist the managers many ways. Jackson is the manager of a company that make electric cars. He would like to use standard costing in his company. Evaluate any TWO (2) advantages and any TWO (2) issues that Jackson will face when implementing standard costing in his company. (10 marks)