It's called Mike's Online Biology: MOB University.

Question

Click physics Tutoring tab -> chapter 9 -> scroll down to question #13 with video below it. I used it as a guide.

Answer 1

I found it all right. He has a pretty convoluted way of explaining it but it is the same thing. I have no idea why he converted to cm^3 rather than to meters^3 from Liters
1000 Liters = 1 m^3
1 Liter = 1000 cm^3
1 m^3 = 1,000,000 cm^3
but it is standard to work in meters, kg and seconds

Answer 2

You understand that he used quite different numbers in his example, D = 2.71 diameter
24 liters instead of 25
1.1 instead of 1.4 min

Answer 3

Yep, it was a bit confusing, but I just looked at what he was doing and used my numbers.