Added 4.1.1. Updated 4.2.1. Error 4.2.2a, 4.2.2b, 4.2.10

Added fully functioning versions of 4.1.1, 4.2.1. 4.2.2a, 4.2.2b, 4.2.10 all exhibit fail due to either a divided by zero error or a float is not iterable error.