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Question How many three-digit prime numbers can you make using each of 2, 4 and 5 once?
2, 4 and 5 cannot form a single prime number.
Because, when its units digit is 2 or 4 it is divided by 2, and when units digits is 5 it is divided by 5 so that’s why 2, 4 and 5 cannot form a prime number.