A, B, C and D are students. They are studying in four different cities, viz., P, Q, R and S (not necessarily in that order). They are studying in Science college, Arts college, Commerce college and Engineering college (not necessarily in that order), which are situated in four different States, viz., Gujarat, Rajasthan, Assam and Kerala (not necessarily in that order). Further, it is given that— (i) D is studying in Assam (ii) Arts college is located in city S which is in Rajasthan (iii) A is studying in Commerce college (iv) B is studying in city Q (v) Science college is located in Kerala Science college is located in

1. **Identify the Goal:** We need to find the location of the Science college. \n\n2. **Analyze Constraints (The 'Anchor'):** Look at the rules given for the Science college. It has a unique property: it has exactly 4 students. (Arts and Commerce have 3 each). This '4' is our unique identifier. [52]\n\n3. **Scan the Options (The 'Target'):** Now look at the cities to find which one holds 4 students.\n - City P: The problem explicitly states it has 3 students (A, C, E).\n - City Q: The list of students staying here is D, G, H, I. Counting them gives exactly 4 students.\n - City R: Holds the remaining students (B, F, J), which is 3.\n\n4. **Apply Logic:** Since Science College is the *only* one with 4 students, and City Q is the *only* city with 4 students, they must be the match. This is a direct 'Cardinality Match' [20]. We do not need to check individual names.\n\n5. **Conclusion:** The Science college is located in City Q.