Question

Find the unit digit of the following exponential numbers:

(i) 64¹¹

(ii) 29¹⁸

(iii) 79¹⁹

(iv) 104³²

Answer 1

(i) 64¹¹ Unit digit of base 64 is 4 and the power is 11 (odd power).

∴ Unit digit of 64¹¹ is 4.

(ii) 29¹⁸ Unit digit of base 29 is 9 and the power is 18 (even power).

Therefore, unit digit of 29¹⁸ is 1.

(iii) 79¹⁹ Unit digit of base 79 is 9 and the power is 19 (odd power).

Therefore, unit digit of 79¹⁹ is 9.

(iv) 104³² Unit digit of base 104 is 4 and the power is 32 (even power).

Therefore, unit digit of 104³² is 6.