Let A={1, 2, 3, 4}. Examine whether the statements given below are true or false.
(i) ∃ x∈A such that x+3=8.
(ii) ∀ x∈A, x+2<7.
(iii) ∃ x↔A such that x+1<3.
(iv) ∀ x∈A, x+3≥5.
(i) Clearly, no number in A satisfies x+3=8.
∴ the given statement is false.
(ii) Every number in A satisfies x+2<7.
So, the given statement is true.
(iii) Clearly, x=1↔A satisfies x+1<3.
∴ the given statement is true.
(iv) Since x=1∈A does not satisfy x+3≥5, the given statement is false.