Answer:
the greatest common factor of 10 and 70 is 10
Well, a rational decimal is like a simple 3.1 or 4.5. It just cuts off easily. Another example would be a repeating decimal like 3.333333...
An irrational decimal is like 3.1415682983523576294875 with no pattern or cutoff point.
Sorry if I am wrong.
Yes he has enough index cards for all students