series

[GmatKiss]

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

[neelgandham]

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

S3 = S2 + S1 = S2 + 4.
S2 = 7-4 = 3. Sufficient to answer the question

(2) S4 = 10

S4 = S3 + S2 = S2 + S1 + S2 = 2S2 + S1.
2S2 + 4 = 10.
S2 = 3. Sufficient to answer the question

IMO D