PT Pandawa has 90% ownership in PT Arjuna. PT Arjuna has 85% ownership in PT Brata, and PT Brata has 5% ownership in PT Arjuna. Separate profits (excluding investment income) of PT Pandawa, PT Arjuna, and PT Brata are IDR 400,000, IDR 160,000 and IDR 220,000, respectively. It is assumed that all investments are acquired at a price equal to book value, and equal to their fair value. 

a. Show mathematical calculations to determine the consolidated net income of PT Pandawa, PT Arjuna, and PT Brata. 

b. Determine the amount of net profit for PT Arjuna and PT Brata using conventional methods. 

c. Determine the controlling interest share and non-controlling interest share of consolidated net income.