Maths Olympiad Prep

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Problem 10

Number theory Difficulty 1.0 Find the answer CEMC Cayley · Canada · 1999

The units digit in the product (52+1)(53+1)(523+1)(5^2+1)(5^3+1)(5^{23}+1) is (A) 00 (B) 11 (C) 22 (D) 55 (E) 66

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