Multiple choice general knowledge sports

what is the unit digit of (2^100- 3^50)

  1. 7

  2. 8

  3. 9

  4. 0
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Find unit digit of 2^100 - 3^50. Unit digits cycle: 2^n → 2,4,8,6 (period 4); 3^n → 3,9,7,1 (period 4). 100 mod 4 = 0, so 2^100 ends in 6. 50 mod 4 = 2, so 3^50 ends in 9. 6 - 9 = -3 ≡ 7 (mod 10). Option A (7) is correct.

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