Answer
$250,000,000$ instructions
Work Step by Step
Given:
- Time slice: 50 milliseconds
- Time to position the read/write head: 8 milliseconds
- Time for the desired data to rotate: 17 milliseconds
Total time spent waiting for a read operation:
= Time to position the read/write head + Time for the desired data to rotate
= 8 milliseconds + 17 milliseconds
= 25 milliseconds
Now, we need to convert the time spent waiting for a read operation from milliseconds to nanoseconds to match the machine's capability of executing instructions.
1 millisecond = 1,000,000 nanoseconds
So, 25 milliseconds = 25,000,000 nanoseconds
Now, we can calculate the number of instructions that can be executed in the time spent waiting for a read operation:
Number of instructions = (Time spent waiting for a read operation) / (Time per instruction)
= 25,000,000 nanoseconds / (1 nanosecond / 10 instructions)
= 25,000,000 nanoseconds * 10 instructions / nanosecond
= 250,000,000 instructions
Therefore, a program can execute 250,000,000 instructions while waiting for a read operation from a disk to take place.
