Question 1191512
P=$5000(0.70)^t, where t is number of years. so if t=0, at the beginning, it is worth $5000, and it is worth $3500 the first year.
800=5000(0.70)^t
divide by 5000
0.16=0.70^t
log (0.16)=t log (0.70)
t=log 0.16/log 0.70=5.14 years
so it will be at 6 or more years