perplexus.info :: Just Math : Prime stars

Prime stars (Posted on 2018-04-13)

*** X *** **** **** **** ******

Each of the asterisks represents a prime digit.

Restore the original multiplication.

No Solution Yet Submitted by Ady TZIDON

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solution

| Comment 1 of 2

there aren't many *** x * = ****

with all prime digits

775x3=2325

535x5=2775

555x5=2775

325x7=2275

As none of the three-digit numbers repeat, the other 3-digit number is a rep-digit.

only the last of them works

325x777=252525

Posted by Jer on 2018-04-13 10:21:03

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