The cost price of the article for P = Rs. 100 (given) ⇒ Cost price of article for Q = 100 × 120% = Rs. 120 ⇒ Cost price of article for R = 120 × (100 – 25)% = Rs. 90 ⇒ Cost price of article for T = 90 × 150% = Rs. 135 ∴ T bought that article at Rs. 135.