SOLUTION: How many prime numbers less than 100 be written using the digits 1,2,3,4,5 if no digit is used more than once? A digit may be used twice?

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Question 1025192: How many prime numbers less than 100 be written using the digits 1,2,3,4,5 if no digit is used more than once? A digit may be used twice?
Found 2 solutions by Alan3354, ikleyn:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!

There aren't many prime numbers from 1 to 100.
List them, see which ones fit.

Answer by ikleyn(52785) About Me  (Show Source):
You can put this solution on YOUR website!
.
How many prime numbers less than 100 be written using the digits 1,2,3,4,5 if no digit is used more than once? A digit may be used twice?
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1. Use this table of prime numbers to answer first question:
   https://primes.utm.edu/lists/small/1000.txt


2. To answer the second question, note that only one sucn number exists. It is 11. 
   Others are multiples of 11.