a. Over a horizontal distance of 1500m, the road will rise 300m. This can be calculated by multiplying the constant slope of 2 in 11 by 300, which gives the result of 1500.
b. The length of the road [AB] is not known, as it depends on the shape of the road. If the road is a straight line, then the length of the road can be calculated using the Pythagorean theorem. However, if the road is curved, then the length of the road cannot be determined without knowing the shape of the road.