31. Assume that Equilibrium GDP is $4,000 billion. Potential GDP is $5,000 billion. The marginal propensity to consume is 4/5 (0.8). By how much and in what direction should government purchases be changed?

a. increase by $1,000 billion c. increase by $100 billion

b. decrease by $1,000 billion d. increase by $200 billion

32. Using the numbers in question 31, by how much should taxes be changed?

a. increased by $1,000 billion c. decreased by $200 billion

b. decreased by $1,000 billion d. decreased by $250 billion

Can you please explain why the answer to Q.32 is D, please?