Manoj, Prabhakar, Mash and Kamal are four friends. Who among them is the heaviest? Statement I: Prabhakar is heavier than Manoj and Kamal but lighter than Akash. Statement II: Manoj is lighter than both Prabhakar and Mash but heavier than Kamal.

Introduction / Context:
This data sufficiency problem asks you to identify the heaviest person among four friends: Manoj, Prabhakar, Mash and Kamal. Two statements give partial comparisons of their weights and mention one additional person, Akash, who is outside the group of interest. The task is to decide whether either statement alone, or the two statements together, allow us to determine exactly which of the four friends is the heaviest.

Given Data / Assumptions:
- Friends within the question: Manoj (M), Prabhakar (P), Mash (H) and Kamal (K).
- Question: Who is the heaviest among M, P, H and K?
- Statement I: Prabhakar is heavier than Manoj and Kamal but lighter than Akash (A). So A > P > M and P > K.
- Statement II: Manoj is lighter than both Prabhakar and Mash but heavier than Kamal. So P > M and H > M and M > K.
- Akash is not one of the four friends we are being asked about; he only provides a comparison point for Prabhakar.

Concept / Approach:
To solve ordering questions, we convert the verbal comparisons into chains of inequalities. For data sufficiency, we check what can be deduced from each statement alone and then from both together. The key question is whether we can identify a single friend among M, P, H and K who is definitely heavier than all three others. If more than one candidate could be heaviest while still satisfying the statements, the data are not sufficient.

Step-by-Step Solution:
Step 1: Analyze statement I alone. From P being heavier than Manoj and Kamal, we know P > M and P > K. However, we have no information about Mash (H) in this statement. Mash could be heavier than P, equal to P, or lighter than P. Hence we cannot determine who is heaviest among the four friends from statement I alone. Step 2: Analyze statement II alone. Manoj is lighter than both Prabhakar and Mash but heavier than Kamal. So we have P > M, H > M, and M > K. Step 3: From statement II we know that Kamal is not the heaviest and that Manoj is not the heaviest because both P and H are heavier than Manoj. Between Prabhakar and Mash, however, we do not know who is heavier. Either P or H could be the heaviest friend. So statement II alone is also not sufficient. Step 4: Combine both statements. From statement I we have P > M and P > K. From statement II we have H > M and M > K and P > M. Step 5: Merging these inequalities gives an order for three of the friends: P and H are both heavier than M, and M is heavier than K. We still have no direct comparison between P and H, so both orders P > H and H > P satisfy all the given conditions. Step 6: Since we cannot decide whether Prabhakar or Mash is heavier, we cannot determine a single heaviest friend among M, P, H and K even when both statements are considered together.

Verification / Alternative check:
To confirm this, consider two possible scenarios consistent with both statements. In the first, suppose H is heavier than P. Then the order could be H > P > M > K. In the second, suppose P is heavier than H. Then the order could be P > H > M > K. Both scenarios satisfy all the given comparisons, but they disagree about who is the heaviest. Because the data admit more than one possible answer, the information is not sufficient.

Why Other Options Are Wrong:
- Option a is wrong because statement I alone does not mention Mash at all, so we cannot identify the heaviest among the four friends.
- Option b is wrong because statement II alone only tells us that both P and H are heavier than Manoj and Kamal, but not which of P and H is heavier.
- Option c is incorrect because neither statement alone is sufficient; each leaves ambiguity.
- Option d is wrong because even using both statements together does not remove the ambiguity between Prabhakar and Mash; both can still be the heaviest in different consistent arrangements.

Common Pitfalls:
A common mistake is to forget that Akash is not part of the set of four friends whose relative weights are being compared. Another pitfall is to assume, without evidence, that Prabhakar is heavier than Mash simply because he is mentioned first or because statement I talks about Prabhakar in relation to someone outside the group. In data sufficiency, you must avoid adding any extra assumptions beyond what is explicitly stated.

Final Answer:
Even when both statements are used together, we cannot uniquely identify the heaviest friend among Manoj, Prabhakar, Mash and Kamal. Therefore, the correct data sufficiency choice is option E.