
Answer:
(i) $940 billion
(ii) $380 billion
(iii) -$80 billion
(iv) $300 billion
Explanation:
Income, Y = $1,500 billion
Government spending, G = $260 billion
Taxes, T = $180 billion,
Investment spending, I = $300 billion
As Y = C + G + I
Consumption spending, C = $1,500 - $260 - $300
                      = $940 billion
Private savings = Y - T - C
             = $1,500 - $180 - $940
             = $380 billion
Public saving = T - G
           = $180 - $260
           = -$80 billion
National saving = private + public
             = $380 - $80
             = $300 billion