OOPS! At 52:18, I switched the numbers $30 and $40 in the solution. The process is correct but I used incorrect numbers. See the back of the book for the correct answers, my explanation will help you understand where the numbers came from. Thanks to the Alderson Family for pointing this out to me!
0:00:14 – #1
0:04:33 – #2
0:07:10 – #3
0:10:11 – #4
0:13:24 – #5
0:21:55 – #6
0:26:57 – #7
0:30:18 – #8
0:32:20 – #9
0:37:14 – #10
0:41:44 – #11
0:47:20 – #12
0:52:18 – #13
1:00:21 – #14
1:06:30 – #15
01:11:35 – #16
01:22:46 – #17
1:26:45 – #18