Calculate autonomous consumption expenditure from the following data

Calculate autonomous consumption expenditure from the following data about an economy which is in equilibrium:
National Income = 1200
Marginal Propensity to Save = 0.20
Investment expenditure = 100

Given,
1 = 100, Y = 1200, MPS = 0.20
MPC or b = 1- MPS = 1-0.20 =0.80
Y = C + l,or C = Y-1=1200-100 =1100
C = $\overline{C}$ + bY
1100 =C +0.80x1200
C =1100-960 =140
Autonomous consumption expenditure © = 140