Given Ts : Transfer time.
b: Number of bytes to be transfered.
N: Number of bytes on a track.
r: Rotational speed.
Which of the following expression gives the total avg access time?
a. Ts+(r/2)+(rb/N)
b. Ts+(1/2r)+(rb/N)
c. Ts+(1/2r)+(N/rb)
d. Ts+(1/2r)+(b/rN)