That is the formula for exponential growth but you're expected to simplify it. For example you're told P_0 (the initial population)
t can be measured in any unit of time but if t is measured in days then k is simply 11.7% expressed as a decimal so days is easiest.
b) The graph is standard exponential with point (0,P_0). If you have to do it by hand then an estimate will be fine as long as you get the shape and intercept right. With software it's easy enough
c) Find P(7) and P(14) respectively
d) P(t) = 2P_0 , solve for t