Answer:
a.

b.

Step-by-step explanation:
a. From the information provided, we can deduce that the population death's follows a Geometric sequence in the form
where
and 
#Since the population is reducing,
can is obtained as 
#The
term is obtained using the formula
, given a=1200
The number of ants alive after every month (in first 4 months)

The ant's alive after 4 months is obtained as the value of 

Hence, 936 ants are alive after 4 months.
b. As with the above question, the kitten population follows a geometric sequence:
.
#Since it's a growing population , the common ration is the sum of 100% + the growth rate,
and
and 
The population after 4weeks will be:
