Question 69588: Give a number that is a counter example to conjecture below. Explain your answer choice.
All numbers that end in the digit 3 are prime.
Answer by bucky(2189)   (Show Source):
You can put this solution on YOUR website! The start of the series of numbers that end in 3 are:
3, 13, 23, 33, 43, 53, 63, 73, 83, 93, 103, ....
Numbers in this series that are not prime are 33 because it factors into 3 times 11; 63 because its factors include 21*3 and 9*7; and 93 because it can be factored into 31*3. Because these are just 3 of the counter examples, the premise that all digits that end in the number 3 are prime cannot be true.
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