Consider the tributaries of the Ganga River: 1. Gandak 2. Kosi 3. Ghaghara 4. Gomti. Which of the following shows the correct order of these rivers from east to west?

Introduction / Context:
The Ganga basin contains many important Himalayan and peninsular tributaries, and exam questions frequently test the ability to place these rivers in correct geographical order. Knowing their relative positions from east to west (or north to south) helps in understanding regional drainage patterns. This question focuses on four major tributaries in the eastern Gangetic plains Gandak, Kosi, Ghaghara and Gomti and asks you to arrange them from east to west as they join or flow towards the Ganga.

Given Data / Assumptions:
- Four tributaries of the Ganga are numbered: 1. Gandak, 2. Kosi, 3. Ghaghara, 4. Gomti. - We must order these rivers from east to west. - All four are important Himalayan or Himalayan fed tributaries in the eastern and central Ganga plains. - The course of each river is considered near its confluence with the Ganga.

Concept / Approach:
The idea is to visualise or recall a mental map of the Ganga basin in Bihar and eastern Uttar Pradesh. Kosi, known for its shifting course, is the easternmost among the given rivers, joining the Ganga in Bihar toward the eastern side. West of Kosi lies the Gandak, another important river entering the Ganga near Patna. Further west, Ghaghara flows through eastern Uttar Pradesh before joining the Ganga near Chhapra or downstream. The Gomti, which rises in the plains and flows through Lucknow, is located even further west and joins the Ganga at Varanasi. Thus, from east to west, the order is Kosi, Gandak, Ghaghara, Gomti, or numerically 2 – 1 – 3 – 4.

Step-by-Step Solution:
Step 1: Identify Kosi as the easternmost river among the four; it enters Bihar from Nepal and meets the Ganga towards the east. Step 2: Recognise that Gandak lies west of Kosi; it also emerges from Nepal and meets the Ganga near Patna. Step 3: Note that Ghaghara flows further west, through eastern Uttar Pradesh, and then joins the Ganga downstream of the Gandak. Step 4: Recall that Gomti rises near the plains in Uttar Pradesh, flows through Lucknow and joins the Ganga at Varanasi, making it the westernmost of the four. Step 5: Convert this spatial arrangement into numerical order: Kosi (2), Gandak (1), Ghaghara (3), Gomti (4), giving 2 – 1 – 3 – 4.

Verification / Alternative check:
You can cross check by remembering key cities near these rivers. Kosi is often associated with floods in north Bihar. Gandak is linked with areas near Patna. Ghaghara flows near Gorakhpur and beyond, and Gomti is famous for flowing through Lucknow before joining the Ganga at Varanasi. Plotting these cities mentally from east (Bihar) to west (eastern to central Uttar Pradesh) confirms that the order from east to west is Kosi, Gandak, Ghaghara, Gomti. This validates the chosen sequence.

Why Other Options Are Wrong:
3 – 4 – 1 – 2 is wrong because it places Ghaghara and Gomti in the eastern positions, which contradicts their actual locations west of Kosi and Gandak.

2 – 3 – 1 – 4 is wrong because it suggests Kosi, Ghaghara, Gandak and then Gomti, incorrectly placing Ghaghara east of Gandak.

1 – 2 – 4 – 3 is wrong since it starts with Gandak before Kosi and swaps the positions of Ghaghara and Gomti, all of which conflict with the real map.

Common Pitfalls:
Candidates often confuse the relative positions of Kosi and Gandak because both originate in Nepal and flow through Bihar. Another mistake is to assume that rivers which join further downstream on the Ganga must automatically be further east, which is not always true. To avoid such errors, practice drawing simple schematic maps of the Ganga basin and repeatedly marking important tributaries and nearby cities to reinforce spatial memory.

Final Answer:
From east to west, the correct order of these Ganga tributaries is 2 – 1 – 3 – 4 (Kosi, Gandak, Ghaghara, Gomti).