Five friends P, Q, X, Y and Z purchased some notebooks. The relevant information is given below:
- 1.Z purchased 8 notebooks more than X did.
- 2.P and Q together purchased 21 notebooks.
- 3.Q purchased 5 notebooks less than P did.
- 4.X and Y together purchased 28 notebooks.
- 5.P purchased 5 notebooks more than X did.
If each notebook is priced ₹40, then what is the total cost of all the notebooks?
Answer & explanation
Answer: (a) ₹2,600
Statements 2 and 3 give P = 13 and Q = 8; then X = 8, Z = 16 and Y = 20. The five bought 65 notebooks, which cost 65 × ₹40 = ₹2,600.
- From 2 and 3: P + Q = 21 and P − Q = 5, so P = 13 and Q = 8.
- From 5: X = 13 − 5 = 8. From 1: Z = 8 + 8 = 16. From 4: Y = 28 − 8 = 20.
- Total notebooks = (P + Q) + (X + Y) + Z = 21 + 28 + 16 = 65.
- Cost = 65 × ₹40 = ₹2,600.
Remember · Start with the pair of equations that closes on its own (sum and difference), then chain outwards.
Question and answer: UPSC's official GS Paper II (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·