Calculation: Let the actual number be 100x According to the question, ⇒ Number after increase = 100x + 100x × 20/100 = 120x ⇒ Final number = 120x – 120x × 15/100 = 102x ⇒ 102x = 2040 ⇒ x = 20 Initial value of the number = 100x = 2000 Short Trick: ⇒ 100x × 120/100 × 85/100 = 2040 ⇒ 100x = 2000 (initial value of the number)