Answer: 5 second per word is the pace of Casey.
Explanation:
Here the given table is,
Words Types 1 2 7 12
Seconds 5 10 35 60
Since, According to the above table,
The time taken by him for typing 1 word = 5 seconds.
The time taken by him for typing 2 word = 10 seconds
The time taken by him for typing 7 word = 35 seconds
The time taken by him for typing 12 word = 60 seconds
Since, the speed of Casey is constant,
Which is, 1/5 word per seconds.
Thus, the pace per word = 5 second/ word ( Pace = 1/ speed)