SOLUTION: sarah is traveling from city A to b. the distance between these 2 cities is 185 miles and she planned to arrive at city b in 2 hrs 30 minutes. her average speed for the first 1 hr

Question 987555: sarah is traveling from city A to b. the distance between these 2 cities is 185 miles and she planned to arrive at city b in 2 hrs 30 minutes. her average speed for the first 1 hr 40 minutes was 75 miles per hour. but then she realized she should slow down to dive more safely. if she still wanted to arrive at her destination on time , at what speed should she drive.
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39621) (Show Source): You can put this solution on YOUR website!

speed time distance FAST 75 SLOWER r Totals 185

Four variables but not nearly as bad as it appears.

and

and then

You should be able to find r.
Answer by MathTherapy(10555) (Show Source): You can put this solution on YOUR website!

sarah is traveling from city A to b. the distance between these 2 cities is 185 miles and she planned to arrive at city b in 2 hrs 30 minutes. her average speed for the first 1 hr 40 minutes was 75 miles per hour. but then she realized she should slow down to dive more safely. if she still wanted to arrive at her destination on time , at what speed should she drive.

Driving for 1 hr 40 minutes at 75 mph means that she covered a distance of , or , or 125 miles
This means that she still has 60 (185 - 125) miles to cover in 50 minutes () hours, or hour
Therefore, she has to drive at a speed of: , or , or mph
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