How can this be proved to be a tautology using laws of logical equivalence?
((x ∨ y) ∧ (x → z) ∧ (¬z)) → y

Step-by-step explanation:

If we assume that is true, then:

is true

is true

is true

If is true, then is false.

, since is true, then is true

If is false and is true, then is true.

If is true, then is false, as is true and is false, then is true.

Conclusion it's true.

b) 1/3 * 1/5

step-by-step explanation:

each smallest part is 1/15 since the written one is 1/5 and it's divided by 3 equal parts. (1/5 )/3 = 1/15 = 1/3 * 1/5