1998 CEMC Gauss (Grade 7) Problems/Problem 2
The number is tripled. The ones digit (units digit) in the resulting number is
Multiply: The units digit is the rightmost digit, which is 1.
The answer is
-edited by coolmath34
The units digit of a product only depends on the units digits of the numbers being multiplied, which reduces the problem down to , meaning that the units digit is 1 and the answer is .