SOLUTION: Chad drove three times as fast Katy could Pedal. Chad drove 90 miles in 2 hours less than it took Katy to pedal 40 miles. How fast could each of them travel? How long did they tra

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Question 1037625: Chad drove three times as fast Katy could Pedal. Chad drove 90 miles in 2 hours less than it took Katy to pedal 40 miles.
How fast could each of them travel? How long did they travel?
Seriously, thank you guys!
Found 3 solutions by josgarithmetic, ikleyn, MathTherapy:
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
Basic travel rates rule for R rate, T time, D distance, is RT=D.
            RATE       TIME     DISTANCE
Chad        3r         t-2       90
Katy         r          t        40

Form the system of equations and solve it.

Answer by ikleyn(52814) About Me  (Show Source):
You can put this solution on YOUR website!
.
Chad drove three times as fast Katy could Pedal. Chad drove 90 miles in 2 hours less than it took Katy to pedal 40 miles.
How fast could each of them travel? How long did they travel?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The equation is

90%2F3r = 40%2Fr+-2.

Solve by multiplying both sides by 2.

It is easy.


Answer by MathTherapy(10555) About Me  (Show Source):
You can put this solution on YOUR website!

Chad drove three times as fast Katy could Pedal. Chad drove 90 miles in 2 hours less than it took Katy to pedal 40 miles.
How fast could each of them travel? How long did they travel?
Seriously, thank you guys!
Let Katy’s speed be S

Then Chad’s is 3S

Time Katy took to pedal 40 miles: 40%2FS

Time Chad took to drive 90 miles: 90%2F3S, or 30%2FS

Since Chad took 2 hours less than Katy, then we can say that: 40%2FS+=+30%2FS+%2B+2

40%2FS+-+30%2FS+=+2

10%2FS+=+2

2S = 10 ------ Cross-multiplying

S, or Katy’s speed = 10%2F2, or highlight_green%28matrix%281%2C2%2C+5%2C+mph%29%29

Chad’s speed: 3(5), or highlight_green%28matrix%281%2C2%2C+15%2C+mph%29%29



Time Katy took: 40%2F5, or highlight_green%28matrix%281%2C2%2C+8%2C+hours%29%29

Time Chad took: 30%2F5, or highlight_green%28matrix%281%2C2%2C+6%2C+hours%29%29