Front and back wheels of a car have diameters $28$ cm and $35$ cm. To cover $88$ m the front wheel makes how many more (integer) revolutions than the back?

Revolutions equal distance divided by wheel circumference: $\frac{8800}{\pi\times 28}\approx 100$ for the front and $\frac{8800}{\pi\times 35}\approx 80$ for the back. The smaller front wheel makes $100-80=20$ more revolutions.