A$)$ If $C=500+5(Y-T),I=200-50r,$ government spending is $300,$ and taxes are $300.$ Find the equation of the is curve.

B$)$ The money demand function is given by $(\frac{M}{P})d=Y-100r.$ Find the equation of th UM curve if Money supply is $1,000$ and the price level is $2.$ Now solve for equilibrium income and interest rate from the IS$-$LM curves in $($A$)$ and $($B$).$

C$)$ If the money supply is raised to $1,200($and all the other variables are the same$),$ solve for the new equilibrium income and interest rate.