The population of a town has approximately doubled every 17 years since 1950.
the equation P=
where Po is the population of the town in 1950, is used to model the population, P, of the town t years after 1950.
When t=17 yrs
P=2
for 1 year
The equation becomes
P = 
-------------(1)
Our original equation is
----------------------------------(2)
equating expression 1 and 2
Cancelling 
from both sides we get
t/17=k
⇒k=t/17 is the solution.
we are given
f(x)=[x=1]
where bracket means ceiling functions
we know that
Ceiling function returns the least value of the integer that is greater than or equal to the specified number
so, we can check each options
option-A:
At x=-4:
f(x)=[-4-1] =-5
For x<-3:
Let's assume
x=-3.1
f(x)=[-3.1-1] =[-4.1]=-5
so, this interval is TRUE
option-B:
At x=-2:
f(x)=[-2-1] =-3
For x<-1:
Let's assume
x=-1.1
f(x)=[-1.1-1] =[-2.1]=-3
so, this is FALSE
