text problem

[calm venture]

67.5% of the 540 km road between the two cities is paved, while the rest is unpaved. the average speed of the car on paved roads was 25 km/h higher than on unpaved roads. find the speed of the car on a paved road if it took 10 hours to cover the entire road

[solar citrus]

d(paved) = 67.5% × 540 = ...
d(unpaved) = (100%-67.5%)×540 = ...
t(paved)+t(unpaved) = 10
t(unpaved) = 10-t(paved)
v(unpaved) = d(unpaved)/t(unpaved)
v(paved) = v(unpaved)+25 = d(paved)/t(paved)
solve for t(paved), then from there you can get v(paved)