Answer
\begin{array}{l}{\text { average seek time }=20 \text { tracks } \times 0.2 \text { msec/track }=4 \text { msec }} \\ {\text { average latency }=0.5 \text { rev } \times 8.33 \text { msec/rev }=4.17 \text { msec }} \\ {\text { transfer time }=1 / 20 \text { rev } \times 8.33 \text { msec }=0.42 \text { msec }} \\ {\text { So the average access time }=4+4.17+0.42=8.59 \text { msec. }}\end{array}
Work Step by Step
\begin{array}{l}{\text { average seek time }=20 \text { tracks } \times 0.2 \text { msec/track }=4 \text { msec }} \\ {\text { average latency }=0.5 \text { rev } \times 8.33 \text { msec/rev }=4.17 \text { msec }} \\ {\text { transfer time }=1 / 20 \text { rev } \times 8.33 \text { msec }=0.42 \text { msec }} \\ {\text { So the average access time }=4+4.17+0.42=8.59 \text { msec. }}\end{array}
