Question

At noon Mr. White started driving from Boston to Philadelphia at average speed 60 mph. At what time will he arrive if he needs to cover 312 miles?

Answer 1

Mr White will arrive at 5:12 pm or 17:12 hrs

Explanation:

Let

y ----> the distance in miles

x ----> the time i hours

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
`k=(y)/(x)` or
`y=kx`

In this problem we have a proportional relationship between the variables x and y

The constant of proportionality k is equal to the speed

so

The linear equation is

`y=60x`

At what time will he arrive if he needs to cover 312 miles?

For y=312 miles

substitute in the equation and solve for x

`312=60x`

`x=312/60=5.2\ hours`

`5.2\ h=5+0.2=5+0.2(60)=5\ h\ 12\ m`

Mr White will arrive at 5:12 pm or 17:12 hrs