C because if you add them all together
The answer will be 12/20 also = 0.65
Part A : formula for circumference = pi*D or 2piR
for circle A.... 8*pi=25.12
therefore pi=3.14
for circle B.... 3*pi=9.42
therefore pi=9.42/3
pi=3.14
part B : formula for Area =

for circle A.... 50.24=pi*(8/2)sqr...(because diameter/2= radius)
pi=50.24/16
pi=3.14
for circle B... 7.065=pi*(3/2)sqr...
pi=7.065/2.25
pi=3.14
what do you observe?
the values for pi are all equal... therefore pi is constant.
Answer:
part A is C 12h=432
part B is 36 hours
Step-by-step explanation: