A whole number is input into the machine The output is then used as a new input to produce a second output. Rosa says "the last digit of the second output must be a 5." Is Rosa correct? Explain your answer
1 Answer
No Rosa, is not correct. See and explanation below
Explanation:
Let
An even number plus
Then, an even number plus
Therefore
Let
An odd number plus
Then, an odd number plus
Therefore
Therefore Machine 1 can output an even or an odd number
Let
An odd number times
Let
Because
Then:
Therefore Machine 2 can output a number ending in