SOLUTION: Moe and Joe take a car trip. Moe drives at an average speed of 41 mph for the first hour and then they stop for gas for 10 minutes. After filling gas, Joe drives at an average spee

Algebra ->  Customizable Word Problem Solvers  -> Travel -> SOLUTION: Moe and Joe take a car trip. Moe drives at an average speed of 41 mph for the first hour and then they stop for gas for 10 minutes. After filling gas, Joe drives at an average spee      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1013191: Moe and Joe take a car trip. Moe drives at an average speed of 41 mph for the first hour and then they stop for gas for 10 minutes. After filling gas, Joe drives at an average speed of 27 mph for 40 minutes, and then the traffic clears and he gets to drive at an average speed of 60 mph for half hour. Find the average speed of the car on this trip.
Express your answer in mph to two significant figures.
I have tried finding individual distances by multiplying each mph by hr in order to get these and adding all of them together to get a total distance which comes out as 90 miles total. Then I added total times in minutes so 60 min+10 min etc. and I got 140 min. Then I divided 90 miles by 2.33 hrs which came out as 38.6. My answer with significant figures would be 39 but it is wrong.
Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
Assumption: The resting period is included in the whole trip time, maybe the wrong assumption. 

           speed     time           distance
part1       41        1/2            20.5
Gasoline              1/6
part2       27        2/3             18
part3       60        1/2             30
total                1%265%2F6            68%261%2F2


Speed AVERAGE is Distance%2FTime;

%2868%261%2F2%29%2F%281%265%2F6%29, miles per hour;
%28137%2F2%29%286%2F11%29
137%2A3%2F11
highlight%2837%264%2F11%29 miles per hour


The average speed will be a little higher if the time spent buying gasoline is excluded.

Answer by MathTherapy(10553) About Me  (Show Source):
You can put this solution on YOUR website!

Moe and Joe take a car trip. Moe drives at an average speed of 41 mph for the first hour and then they stop for gas for 10 minutes. After filling gas, Joe drives at an average speed of 27 mph for 40 minutes, and then the traffic clears and he gets to drive at an average speed of 60 mph for half hour. Find the average speed of the car on this trip.
Express your answer in mph to two significant figures.
I have tried finding individual distances by multiplying each mph by hr in order to get these and adding all of them together to get a total distance which comes out as 90 miles total. Then I added total times in minutes so 60 min+10 min etc. and I got 140 min. Then I divided 90 miles by 2.33 hrs which came out as 38.6. My answer with significant figures would be 39 but it is wrong. 
Distance covered, driving at 41 mph: 41 *  1 = 41 miles

Distance covered, driving at 27 mph: 27 * 2%2F3 = 18 miles

Distance covered, driving at 60 mph: 60 * 1%2F2 = 30 miles



Total distance covered: 41 + 18 + 30, or 89 miles

Total time taken to drive 68.5 miles: 1+%2B+2%2F3+%2B+1%2F2, or 2%261%2F6 hours

Average speed: 89%2F2%261%2F6, or 89%2F%2813%2F6%29, or 41.07692308 ≈ highlight_green%2841%29 mph

Why would you want to include the time spent getting gas? Is that part of travel time? Last time I checked, it wasn't, and never will be.