Answer
The car should be discounted first before receiving a rebate of $2000.
Work Step by Step
Since from part (c)
R(S(p))=R(0.9p)=0.9p-2000
S(R(p))=S(p-2000)=0.9p-1800
Substitute p=25795:
R(S(25795))=R(0.9*25795)=0.9*25795-2000=21215.50$
S(R(25795))=S(25795-2000)=0.9*25795-1800=21415.50$
R(S(p)) yields a lower cost which means that the car should be discounted first before receiving a rebate of $2000.
