(In this way, we don't have to worry about the exponent very much.) Finally, 2017≡17( mod 100), and thus 20152016−2017≡25−17≡08( mod 100), as above.结果一 题目 What is the tens digit of 20152016−2017?( )A.0B.1C.3D.5E.8 答案 A相关推荐 1What is the tens...
Notice that, for n⩾2, 2015n≡15n is congruent to 25( mod 100) when n is even and 75( mod 100) when n is odd. (Check for yourself). Since 2016 is even, 20152016≡25( mod 100) and 20152016−2017≡25−17≡08( mod 100). So the answer is (A)0. In a very simi...