In a certain city 90% of the population own a motor cycle, 15% own a car and every body owns a car or a motor cycle or both. What percent of the population of that city own a car but not a motor cycle?

As per the question,

Percentage of people own motorcycle $$=90\%$$

Percentage of people own car$$=15\%$$

Let total population of the village =100

Total  number of people who do not own the motorcycle $$=100-90=10$$

As per the question, it is given that, every people of the village own either car or motorcycle or both.

But as per the above, 10% people don't own motorcycle, Hence, 10% people own Car but not motorcycle.