if the speed of a car is increased from 90km/h to 120km/h, the time is reduced by one hour to reach the destination. Calculate the distance between the two towns.

Answer 1

let the distance be d km

time at 90 km/h ---- d/90
time at 120 km/h --- d/120

d/90 - d/120 = 1

solve for d

hint: multiply each term by 360 to clear fractions