JNU SSS 2010 Question 59: Keynesian cross and the multiplier

Suppose, in equilibrium, aggregate income (in units of money per year) in an economy $Y = C + I$, where investment expenditure (in units of money per year) $I = 1000$ and aggregate consumption expenditure (in units of money per year) $C$ satisfies the following conditions : (i) $C$ is a function of current disposable income in the economy $(Y_d)$ (ii) If $Y_d = 0$, then $C = 500$ (iii) Marginal propensity to save out of $Y_d$ is constant in the economy and equal to 30% Suppose the government collects direct tax revenues equal to 15% of $Y$ and makes direct transfer payments equal to 750 units of money per year.

What is the equilibrium value of $Y$ in the economy?