IBPS PO Mains 30 Nov 2024 Shift 2 Paper

Concept:When a train crosses a platform, the distance covered equals the train length plus the platform length.For two trains moving in the same direction, the relative speed equals the difference of their speeds.The data are sufficient only when the number of independent equations equals the number of unknowns and a consistent, valid value is obtained.Explanation:Let the length and speed of Train G be $L_G$ and $S_G$; use similar notation for Trains H and J.Statement I: It gives $L_G + 280 = 10.4S_G$ and $L_G + L_H = 20(S_G - 30)$.These are two equations with three unknowns ($L_G$, $S_G$, $L_H$), so Statement I alone is insufficient.Statement II: It gives $L_J + 320 = 20S_J$ and $L_J + L_G = 72(S_G - S_J)$.These are two equations with four unknowns ($L_G$, $S_G$, $L_J$, $S_J$), so Statement II alone is insufficient.Statement III: It gives $L_G = 240$, with $L_H + 180 = 18S_H$ and $L_H + 240 = 30(S_G - S_H)$.These are two equations with three unknowns ($L_H$, $S_H$, $S_G$), so Statement III alone is insufficient.Combining statements: Statements I and III describe the same crossing event of Trains G and H, but they give different times, $20$ seconds and $30$ seconds, which is contradictory.Hence the statements cannot be combined to produce a valid answer.The other combinations also fail to give a unique or consistent value of $S_G$.Therefore, the given data are neither sufficient nor consistent.Answer:None of the statements, alone or together, are sufficient to determine the speed of Train G.Correct option: E (None are sufficient).