In a two sector economy , the Saving function is : S = -100 + 0.5Y.
The Autonomous Investment expenditure in the economy is Rs. 100
crore. Find out : 
a) Autonomous consumption expenditure and Marginal propensity to
consume.
b) Break-even level of income.
c) Equilibrium level of National Income.
d) Consumption expenditure and Savings at Equilibrium level of
National Income.

Dear Student,

As we know that: Y = C + S
C = Y - S
C = Y - (-100 + 0.5Y)
C = 100 + 0.5Y
C = c + bY
(a) Autonomous consumption = 100
Marginal propensity to consume(MPC) = 0.5
​​​​​​
​(b) Break-even level of income, i.e., point when C=Y
C = 100 + 0.5Y
Y = 100 + 0.5 Y
0.5Y = 100
Y = 200
Hence, the break-even level of income is Rs.200 crore

(c)  Equilibrium level of income, i.e., point when AD = AS
Y = C + I
Y = 100 + 0.5Y + 100
0.5Y = 200
Y = 400
Equilibrium level of Income = Rs.400 crore

(d) At equilibrium level of income, i.e., Y = Rs.400 crore
C = 100 + 0.5Y = 100 + 0.5(400) 
C = Rs.300 crore

S = -100 + 0.5Y = -100 + 0.5(400) 
​​​​​​S = Rs.​100 crore

Regards