Question

a family takes 2 1/2 hour to drive from their house to a lake at 48mi/h. the travel time varies inversely with the speed of the car. how long will the return trip take at 40 mi/h?

Answer 1

if it takes 2 1/2 hours going 48 mph we can figure out how many miles it was with
2 1/2*48=120
they went 120 miles to the lake
now they are going back the 120 at 40 mph
120/40=3
it took 3 hours for the return trip