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Question

in a far city 90% of the population own a cycle. 15% own a car and everybody owns a cycle  or car or both. what % of the population own a car but not a cycle

 

(a)10%

(b)20%

(c)30%

(d)40%

Answer 1

Answer:

 

Well, If everyone owns a car or a cycle, that means 100% of the population owns something, right? So if no one owned both, and if 90% own a cycle and 15% own a car, together that's 105% of people. Obviously there cannot be more than 100% of people, so some people must own both. How many own both? well since everyone has to own something, only 5% of the population can own both, because if more owned both, for example, if 10% of the population owned both, then 80% of people would own only cycles, 5% would own only cars, 10% of people would own both, and only 95% of the population would own anything, therefore not all of the population would own a car or cycle. Since the 5% of the population that owns both is accounted for in the 15% of people that own cars, 15-5=10 so 10% of people own cars but not cycles.