In the infinite series S1, each term Sn after S2 is equal to the sum of the two terms S(n-1) and S(n-2). If S1 = 4, what is the value of S2 ?
(1) S3 = 7
(2) S4 = 10
(1) S3 = 7
(2) S4 = 10
S3 = S2 + S1 = S2 + 4.(1) S3 = 7
S2 = 7-4 = 3. Sufficient to answer the question
S4 = S3 + S2 = S2 + S1 + S2 = 2S2 + S1.(2) S4 = 10
2S2 + 4 = 10.
S2 = 3. Sufficient to answer the question
IMO D
