Question

Please help with word problem?

Answer 1

when driving a car the amount of time traveled varies inversely with the speed of the car. two friends take turns driving the 240 mile journey between their home and summer camp. francesca drives an average speed of 50 miles per hour for the first two-fifths of the trip. sam drives the remaining three-fifths of the trip at an average speed of 60 miles per hour.
A) how long are francesca's and sam's portions of the trip? what is the total amount of time traveled?
B) how would the total amount of time change if francesca drove at 60 mi an hour and sam drove at 50 mi per hour?

Answer 2

Is this correct, A)
F = 240mi * 0.4 / 50mi/hr = 1.92hr
S = 240mi * 0.6 / 60mi/hr = 2.40hr
1.92hr + 2.40hr = 4.32hrs

B)
F = 240mi * 0.4 / 60mi/hr = 1.60hr
S = 240mi * 0.6 / 50mi/hr = 2.88hr
1.60hr + 2.88hr = 4.44hrs