In the following pie-chart, the distribution of the number of cars in four major cities is given. In…

As a share of the total cars in the four cities, petrol cars in City C account for $\frac{3}{8} \times 32\%$ $= 12\%$ (or $17,640$ cars), while petrol cars in City A account for $\frac{4}{7} \times 14\%$ $= 8\%$ (or $11,760$ cars). Therefore, the number of petrol cars in City C exceeds that in City A by $\frac{12 - 8}{8} \times 100\%$ $= \frac{17,640 - 11,760}{11,760} \times 100\%$ $= 50\%$.