1. (15 pts.) Consider the mod 10 multiplication table (see the table on the right, below):

a. Which rows contain a value of 1? {in increasing numerical order} ____, ____, ____, ____.

b. These rows and no others contain a value of 1 because they are the only ones that are ________ to 10.

c. These numbers are significant for mod-10 arithmetic because only these numbers have ______, mod 10.

Enter a modulus value >1, and click Generate