A population of rabbits follows the law of uninhibited growth. There are 5 rabbits initially and after 4 months there are 35. a.) How many rabbits will there be in one year? b.) How long will it take for the initial population to triple?

1 Answer
Jun 25, 2017

a) Rabbit population after #12# months is #1715# and b) will tripple , i.e #15# after # 2.2583# months.

Explanation:

The formula for uninhibited growth of rabbit is #P_t=P_i*e^(kt)# ,

where #P_t,P_i,k,t# are population, initial population,

growth constant, and period in months.

#P_4=35 , P_i=5,t=4 , k = ? :. 35 =5*e^(k*4) or e^(4k) =7 #. Taking log on both sides, we get,

#4k=ln7 ; [lne=1] or k =ln7/4 = 0.486478#

a) #k= 0.486478 , P_12=? :. P_12 = P_i*e^(kt) # or

# P_12 = 5*e^(0.486478 *12) = 1715 #

b) #P_t=15 ; t =? :. 15 = 5 * e^(0.486478*t) # or

#e^(0.486478*t) = 15/5=3# Taking log on both sides, we get,

#0.486478*t= ln 3 :. t= ln3/0.486478= 2.2583# months

a) Rabbit population after #12# months is #1715# and b) will tripple ,

i.e #15# after # 2.2583# months [Ans]