A1000 gallon tank, initially full of water, develops a leak at the bottom. given that 300 gallons of water leak out in the first 30 minutes, find the amount of water, a(t), left in the tank t minutes after the leak develops if the water drains off at a rate proportional to the amount of water present.

a. a(t)= 1000(1/3)^1/10t
b. a(t)= 1000(1/2)^-1/10t
c. a(t)= 1000(1001/2)^t
d. a(t)= 1000e ^-1/10t
e. a(t)= 1000(1/2)^1/10t
f. none of these