Question

erika drove 280 miles in 5.5 hours. She averaged 40 miles per hour driving through towns and cities . She averaged 55 miles per hour driving on the highway. How many hours did Erika drive on the highway?

Answer 1

Erika drove 4 hours on the highway

Answer 2

As per the problem

Erika drove 280 miles in 5.5 hours.

She averaged 40 miles per hour driving through towns and cities .

She averaged 55 miles per hour driving on the highway.

Let Erika drive on high for "t" hours on highway.

Then driving time other than highway
`=(5.5-t) \ hours\\`

As we know that
`\text{Distance=Speed*Time}\\ \\\text{Hence from the given data we can setup the equation as below}\\\\`

`40(5.5-t)+55(t)=280\\\\\text{Simplify we get}\\\\ 220-40t+55t=280\\\\\text{Take the like terms together and simplify we get}\\\\55t-40t=280-220\\\\15t=60\\\\t=4\\`

Hence for 4 hours Erika drove on the highway.