From the question, we can deduce the following:
320 pages ==> 32 hours
Let's find how many pages Kenneth will read in 42 hours.
We have:
32 hours = 320 pages
42 hours = x pages
Apply the proportionality equation and solve for x.

Cross multiply:

Divide both sides by 32:

Therefore, Kenneth will read 420 pages after a total of 42 hours.
ANSWER:
420 pages.