Ice cream machine problem solving

I don’t understand the logic behind the answer. Can someone please provide an alternative solution?

Each machine contributed 80 minutes of work in order to complete one Order of Ice Cream. Since they run concurrently, this would mean it takes 8 hours, or 480 minutes of work to produce a single order of Ice cream.

In the case that one of these machines breaks, since once again they run concurrently, it will logically take longer to produce that order.

To compensate for the wasted time and product needed, the work of the broken machine must be divided into the 5 machines left. Remembering that the total time with 6 machines was 480 minutes- we now divide this time across the 5 machines {\frac {480}{5}} is 96 minutes, making the correct Answer C.