Jacky leaves the office at 4:15 PM. If
she reaches her house at 4:55 PM
when her house is 25 km away from
her office, approximately, how fast did
she drive?

Respuesta :

Given:

Jacky leaves the office at 4:15 PM and she reaches her house at 4:55 PM.

Distance between office and her house = 25 km

To find:

The driving speed of Jacky.

Solution:

The difference between 4:15 PM and 4:55 PM is 40 minutes.

60 minute = 1 hour

1 minute = [tex]\dfrac{1}{60}[/tex] hour

40 minute = [tex]\dfrac{40}{60}[/tex] hour

                 = [tex]\dfrac{2}{3}[/tex] hour

We know that,

[tex]Speed=\dfrac{Distance}{Time}[/tex]

[tex]Speed=\dfrac{25}{\dfrac{2}{3}}[/tex]

[tex]Speed=\dfrac{3\times 25}{2}[/tex]

[tex]Speed=\dfrac{75}{2}[/tex]

[tex]Speed=37.5[/tex]

Therefore, the driving speed of Jacky is 37.5 km per hour.