Answer and Explanation:
a. The amount that the government spending have to rise to shift the aggregate demand curve rightward by $25 billion is $5 million
Thus:
The multiplier is 1/1-0.8 = 1/0.2 = 5 million
Tax cut would be necessary to achieve the same increase in aggregate demand is $6.25 billion which is = (5 /0.8).
The part of tax saving is going to be:
($6.25 -$5 =$1.25 billion)
b. One possible combination is $1 billion on government spending, and tax cut will decrease in $5 billion in order to accomplish the same goal.