SOLUTION: A car travels 2 hours at uniform speed. If it will slow down to 1/2 of original speed, the car reaches its destination 30 minutes later covering a total distance of 84 km. What is

Click here to see ALL problems on Travel Word Problems

Question 884670: A car travels 2 hours at uniform speed. If it will slow down to 1/2 of original speed, the car reaches its destination 30 minutes later covering a total distance of 84 km. What is the original speed?
Found 2 solutions by josgarithmetic, lwsshak3:
Answer by josgarithmetic(39620) (Show Source):
You can put this solution on YOUR website!
RT=D Key Concept Equation

Let r = original speed

__________________rate_________time________distance
Regular___________r____________2___________(_____)
Half-speed________r/2__________1/2_________(_____)
TOTAL______________________________________84

Unfinished intentionally, but this initial set-up should be quickly and effectively helpful.

Answer by lwsshak3(11628) (Show Source):
You can put this solution on YOUR website!
A car travels 2 hours at uniform speed. If it will slow down to 1/2 of original speed, the car reaches its destination 30 minutes later covering a total distance of 84 km. What is the original speed?
***
let x=original speed
distance=travel time*speed
..
2x+x/2*1/2=84
2x+x/4=84
9x/4=84
9x=336
x=37-1/3 km/hr
original speed=37-1/3 km/hr