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Which Prime Numbers?

Number Theory Level 1

I have 2 prime numbers.

The last digit of the sum of these 2 prime numbers is 9.

What is the last digit of the product of these 2 prime numbers?

4 5 6 7

View solutions

Excel in math and science

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It's hard to learn from lectures and videos

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including olympiad champions, researchers, and professionals.

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by Pi Han Goh

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