Tips & Tricks Given: Price of rifle depreciates 10% every year Concept used 10% = 1/10 Calculation: Every year price reduces by 10%m, that is, if at starting of year price = 10x then at the end of year price = 9x ⇒ For two years combined, Price at start =10x×10x=100x2, Price at end of 2 years = 9x×9x=81x2 ∴ Price at start =100x2=INR82000 ⇒ x2= INR 820 After 2 years, value of rifle becomes = 81x^2 = 81 × INR 820 = INR 66420 ⇒ Value of rifle after 2 years = INR 66420 Short trick: Value of rifle after 2 years = (9/10) × (9/10) × 82000 ⇒ Value of rifle after 2 years = INR 66420