You can solve this problem by using the following rule of three:
42 s ----> 0.5 DVD
x ----> 1 DVD
Clearing x:
x = (1 / 0.5) * (42)
x = 84 s (time to complete a DVD)
Then, we have the following conversion:
1min = 60s
So:
x = (84/60)
x = 1.4 min
The rate is then:
rate = 1 / 1.4 = 0.71 DVD / minute
Answer:
Jaytree's "ripping rate" in DVDs per minute is
0.71 DVD / minute