Question

It's my last question. Please help!!

Answer 1

Alex wrote the following indirect proof:

Prove: 13 is a factor of 195
Step 1: Assume that 13 is not a factor of 195.

Step 2: 195 divided by 13 is 15.
Step 3: A factor is an integer by which another integer is a multiple.

Step 4: Therefore, 13 must be a factor of 195.
Which step in Alex's proof is incorrect?

Answer 2

Step 3?

Answer 3

yup its 3 but no one helped.