So exponenetial growth or decay
it goes like this
f(t)=P(1+r)^t
r=rate of decay or grouth
if r>0 then it is grouth by r
if r<0 then it is decay
i
P=initial amount
so
given
f(x)=5500(1.65)^t
f(x)=5500(1+0.65)^t
0.65>0 so it is growing by 65%
The circumference of a circle is 
Circumference = 
It says to leave in terms of pi which means that we won't solve 
Thus the answer is
.
Hope that helped!