Answer:
2000? ... assume $2000
Resale Value = $2000*(1 - 0.25)t/yr
where: t = number of year after purchase
at t = 3 yr
Resale Value = $2000*(1 - 0.25)3 = $843.75
checking: at t = 0 $2000 (purchase price)
at t = 1 yr $2000 - 0.25*$2000 = $2000 - $500 = $1500
at t = 2 yr $1500 - 0.25*$1500 = $1500 - $375 = $1125
at t = 3 yr $1125 - 0.25*$1125 = $1125 - $281.25 = $843.75