2. How many bit strings of length 12 containa) exactly three 1s? b) at most three 1s? c) at least three 1s? d) an equal number of 0s and 1s?

Question

Leyla Townsend

Computers & Technology

20 April, 19:37

2. How many bit strings of length 12 containa) exactly three 1s? b) at most three 1s? c) at least three 1s? d) an equal number of 0s and 1s?

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Answers (1)

Know the Answer?

Jack Bailey · Answer 1

The answers are: 220, 299, 4017, and 924.

Explanation:

a) (¹²₃) = 220

b (¹²₀) + (¹²₁) + (¹²₂) + (¹²₃) = 1 + 12+66+220 = 299.

c) 2¹² - 66-12-1 = 4017

d) (¹²₆) = 924