If you can't divide it, it depends on whether it is greater than 10 or less than 10, and then determine what 30 and 20 are respectively.
After six cycles, the end saw, but actually saw 6x2- 1= 1 1 times.
The total sawing time is 8+2= 10,
It can be seen that it takes11x10 =110 minutes to finish sawing.