SOLUTION: Sharon drove for part of a 150 km trop at 45 km/h and the rest of the trop at 75km/h. How far did she drive at each speed if the entire trip took her 2h 40 mins.
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-> SOLUTION: Sharon drove for part of a 150 km trop at 45 km/h and the rest of the trop at 75km/h. How far did she drive at each speed if the entire trip took her 2h 40 mins.
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: Sharon drove for part of a 150 km trop at 45 km/h and the rest of the trop at 75km/h. How far did she drive at each speed if the entire trip took her 2h 40 mins. This question is from textbook
You can put this solution on YOUR website! Sharon drove for part of a 150 km trop at 45 km/h and the rest of the trop at 75km/h. How far did she drive at each speed if the entire trip took her 2h 40 mins.
:
Let d = distance driven at 45 km/h
Then
(150-d) = distance driven at 75 km/h
:
Change 2:40 to hrs: 120 + 40 = 160 min = 160/60 = hrs
:
Write a time equation: Time = distance/speed
:
Time at 45 km/hr + time at 75km/hr = hrs + =
:
Multiply equation by 450 to get rid of those annoying denominators:
:
450* + 450* = 450*
:
Cancel out the denominators and we have:
10d + 6(150 - d) = 150(8)
:
10d + 900 - 6d = 1200
:
10d - 6d = 1200 - 900
:
4d = 300
:
d =
:
d = 75 km at 45 km/hr
then
150 - 75 = 75 km at 75 km/hr
:
:
Check solution by finding the time:
75/45 + 75/75 = + = ; confirms our solutions
