On a 130 mile trip, a car traveled an average speed of 55mph and then reduced its speed to 40 mph for the remainder of the trip. The trip took 2.5 hours. For how long did the car travel at 40mph ?
Q. On a 130 mile trip, a car traveled an average speed of 55mph and then reduced its speed to 40 mph for the remainder of the trip. The trip took 2.5 hours. For how long did the car travel at 40mph ?
Set Up Total Time Equation: Let t1 be the time the car traveled at 55 mph and t2 be the time at 40 mph. The total time is given as 2.5 hours. Set up the equation for total time:t1+t2=2.5
Set Up Distance Equations: Use the distance formulaD=R×T for each part of the trip. The total distance is 130 miles. Set up the equations for distances:55t1+40t2=130
Solve System of Equations: Solve the system of equations:1. t1+t2=2.52. 55t1+40t2=130Multiply the first equation by 40:40t1+40t2=100Subtract this from the second equation:55t1+40t2−(40t1+40t2)=130−10015t1=30t1=2
Substitute and Solve: Substitute t1=2 back into the total time equation:2+t2=2.5t2=0.5
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