Time conversions

Change 12,345 seconds into hours, minutes and seconds.

Change 1,776 minutes into days, hours and minutes.

Answers in the comments.

Practice problems for logic and tautology

The text editor for this blog doesn't have any arrow symbol, either for mapping or for implication. Instead, the mapping arrow will be written as -> and the implication arrow will be =>.

For all these problems, let p = 1100 and q = 1010. Determine if the following logical statements are tautologies (all 1's), contradictions (all 0's) or conditional (some 1's and some 0's).

Problem 1.
(p v q) => ~p
Problem 2.
p v (q => ~p)

Problem 3.
(p ^ q) => ~p

Problem 4.
(p ^ ~p) => q


Answers in the comments.

Practice problems for homework 5

Link to a set of contingency table problems.

Sets to bitstrings and vice versa.

Let the universal set U = {red, orange, yellow, green, blue, violet} in that order.

Change sets into bitstrings of length six.

{red, yellow, blue} -> ___________

{red, orange, yellow} -> ____________

{orange, violet} -> ____________

Change bitstrings into sets.

10 0111 -> _______________

01 0101 -> _______________

00 000 -> _______________

Answers to the set and bitstring questions in the comments.