Question

G, P and S are animal species. What is the average life span in years of S?
I. The average life span of S is twice that of P and $\frac{4}{5}$that of G.
II. The average life span of G is 30 yr longer than that of P and 10 yr longer than that of S
Decide whether the data in the statements are sufficient to answer the question.

• A. if Statement I alone is sufficient but Statement II alone is not sufficient to answer the question
• B. if Statement II alone is sufficient but Statement I alone is not sufficient to answer the question
• C. if both statements taken together are sufficient to answer the question but neither Statement alone is sufficient
• D. if Statements I and II together are not sufficient, and additional data is needed to answer the question

Answer 1

Answer: (C)

if both statements taken together are sufficient to answer the question but neither Statement alone is sufficient

Answer 2

Statement 1:
$S=2P$
$S = \frac{4}{5} G$
we cannot determine.
Statement 2:
$G=P+30$
$G=S+10$
we cannot determine.
Both statements:
$S = \frac{4}{5} G \quad \text{and} \quad S = \frac{4}{5} G$
So,
$S = \frac{4}{5} (S + 10)$
$\frac{1}{5} S = 8$
$S=40$
So, we can determine using both the statements together. So the correct option is (C)