26/5 is 5.2 as a fraction
Answer:
20 seconds
Step-by-step explanation:
I assume you mean 
for your function.
As the given function is in the form of 
(some textbooks may write this formula differently), the period is equal to 
. Hence, the period of the given function is 
, or 20 seconds.
Use the formula,
I = Prt
P = Principal amount = 400
I = interest = 18
r = annual rate
t = time in years = 9/12 = 3/4
so,
18 = 400*r*3/4
r = 0.06
so the annual interest rate is 0.06 or 6%.
16.25pi
You can get this by first solving for volume of a cylender formula for the 1.5 radius of the outer shell. Then solve for a 1 radius of the inner empty portion. Then subtract the second from the first.
