Some students are having trouble getting to the answer on Q3 on the sample paper. Here's a rough guide to the solution.
National income is GDP minus depreciation.
GDP is C+I+G+X-M. So from the sample exam, here we have
GDP = 4750+900+1400+810-850 = 7010.
National Income = GDP – 450 (depreciation) = 7010-450 = 6560.
Personal income is national income less corporate profits, less income taxes, and plus transfer payments.
So we have 6560-50-600+700 = 6610.
Personal disposable income is personal income minus personal taxes.
Personal disposable income is 6610- 800 = 5810.
Hope this helps, good luck with the exam tomorrow, I'll see everyone there.