CÂU HỎI 7 (SINGLECHOICE)
Let S be the subset of the set of ordered pairs of integers
defined recursively by
Basis step: (0,0) = S.
Recursive step: If (a, b) = S, then (a + 2, b + 3) = S and
(a+3, b+2) = S.
Which element is in S?
(8,15)
(12,15)
(10,15)
(9,15)
