SOLUTION: Half an hour after leaving her house Sarah was 25 miles from home. She then got on the freeway and traveled at a constant speed for several hours. 4 hours after leaving home Sarah

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Question 1046459: Half an hour after leaving her house Sarah was 25 miles from home. She then got on the freeway and traveled at a constant speed for several hours. 4 hours after leaving home Sarah had traveled a total of 245 miles.
How far did Sarah travel in 1.75 hours on the freeway, and how do you know?

Answer by josgarithmetic(39618) About Me  (Show Source):
You can put this solution on YOUR website!
                      RATE         TIME         DISTANCE
HALF HOUR START                   1%2F2           25
FREEWAY                            t             d

Totals                             4           245


The asked question is what distance for 1.75 hours on the freeway. The unknown time and distance in the table above can be found, and the speed done on the freeway can then be found.

Use the sums for the "Totals" from the table.

t%2B1%2F2=4
t=3%261%2F2
-
d%2B25=245
d=245-25
d=220
-
Speed used on the freeway was d%2Ft=220%2F%283%261%2F2%29=220%2F%287%2F2%29=440%2F7, miles per hour. Now you "know".

How far Sarah travel in 1.75 hours while at 440%2F7 miles per hour?