SOLUTION: Jerry had a doctor's appointment at 10:00 am. The doctor's office is located 16.2 miles away from Jerry's house. John got in the car at 9:30 am, drove with an average speed of 25.4

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Question 985215: Jerry had a doctor's appointment at 10:00 am. The doctor's office is located 16.2 miles away from Jerry's house. John got in the car at 9:30 am, drove with an average speed of 25.4 mph.
Jerry ended up being late for the appointment. How much faster should he have driven (in mph).

Found 2 solutions by josgarithmetic, MathTherapy:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!

rate     time     distance
25.4     t+x       16.2



If t was expected time and x was the excess time, you have t%2Bx=1%2F2.

This system can be formed:
system%28%2825.4%29%2A%28t%2Bx%29=16.2%2Ct%2Bx=1%2F2%29

Two linear equations in the variables, t and x;
both can be found. These as set with the equations, will be in hours (actually fractions of an hour).

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!

Jerry had a doctor's appointment at 10:00 am. The doctor's office is located 16.2 miles away from Jerry's house. John got in the car at 9:30 am, drove with an average speed of 25.4 mph.
Jerry ended up being late for the appointment. How much faster should he have driven (in mph).
Speed+=+Distance%2FTime
Time to get there: 30 minutes, or 1%2F2 hour
Speed at which he needs to drive to get there in exactly 30 minutes: Speed+=+16.2%2F%281%2F2%29, or 32.4 mph
Actual speed he traveled at to get there late: 25.4 mph.
So, he should've travelled at least highlight_green%287%29 (32.4 - 25.4) mph faster to get there in EXACTLY 30 minutes, or 1%2F2 hour