I drove to my parents' house at 60 miles per hour. If I had driven 50 miles an hour instead, then I would have gotten there 40 minutes later. How many miles did I drive?

Thank you!

HelpPLZ
Sep 18, 2018

#1**+3 **

The DISTANCE is the same regardless of the SPEED.

Let x = amount of hours required at 60 MPH

then x+ 40/60 = hours required at 50 MPH

Since the distance is equal:

60 * x = 50 (x + 40/60) Then slove for 'x' = 3 1/3 hr

60 mph takes 3 1/3 hr = 60 x 3 1/3 miles = 200 miles

ElectricPavlov
Sep 18, 2018

#4**+1 **

Let D be the distance...and 40 min = 2/3 hr

And rate * time = distance.....but the distances are the same...so ...we can make an equation involving the times

Adding 40min = 2/3 hr to the time it takes driving 60 mph = the time it takes driving 50 mph....so...

D / 60 + 2/3 = D / 50 rearrange as

2/3= D/50 - D / 60

2/3 = [ 60 - 50 ] D / 3000

2/3 = 10D / 3000

2/3 = D/ 300 multiply both sides by 300

300 (2/3) = D = 200 miles

CPhill
Sep 20, 2018