Given, Number of residents of a housing society own cars is = 11/16 of total residents Number of residents of car owners have purchased covered parking space = 20/33 of the car owners Number of residents who parked their car in open = 130 Concept: If any fraction decreases by a/b, then, Remaining value = (1 – a/b) × Actual value Calculation: Let the total number of residents of a housing society be x Number of residents who own cars = x × 11/16 = 11x/16 ⇒ Number of residents who have covered parking space = (11x/16) × (20/33) = 5x/12 ⇒ Number of residents who park their car in open = 11x/16 – 5x/12 = 13x/48 According to the question 13x/48 = 130 x = 130 × (48/13) x = 480 ∴ Number of resident in the society is 480