Question

The digits 1, 2, 3, 4, 5, 6, 7, and 9 are used to form four two-digit prime numbers, with each digit used exactly once. What is the sum of these four primes

Answer 1

Answer: 190

Step-by-step explanation: i just did Aops

Answer 2

190

Explanation:

The even digits and 5 cannot be in the units place of any 2-digit prime. That means the sum must be ...

(2 +4 +5 +6)×10 +(1 +3 +7 +9) = 170 +20 = 190

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There are several ways the set of primes can be created. A couple are ...

{23, 41, 59, 67} or {29, 47, 53, 61}