Question

Gilda drove 650miles at an average speed of 50 miles per hour.how many miles per hour faster would she have had to drive in order for the trip to have 1 hour less?

Answer 1

T=650mi(hr/50mi)=13 hr

t-1=12 hr

12=650/(50+v)  multiply both sides by 50+v

600+12v=650  subtract 600 from both sides

12v=50  divide both sides by 12

v=25/6 mph

v≈4.17mph