Question

Evan is just leaving his house to visit his grandmother. Normally, the trip takes him 35 minutes on the freeway, going 70 mph. But tonight he's running 5 minutes late. How fast will he need to drive on the freeway to make up the 5 minutes?

Answer 1

Answer:

Evan drive at speed = 81.67 m/hr

Explanation:

Normal speed of Evan = 70 m/hr

Time taken by Evan to visit his grandmother = 35 min = $\frac{35}{60}$ hr

Distance covered by Evan = ${speed}\times{time taken}$ = $70\times\frac{35}{60}$

                                            = $\frac{245}{6}$ miles

According to the problem, one day Evan was running 5 minutes late. So, the time Evan has to visit his grandmother is 30 mins.

To reach on time, Evan should be drive at the speed :

Speed = $\frac{Distance}{Time}$

           = $\frac{\frac{245}{6} }{\frac{30}{60} }$

          = 81.67 m/hr