Rational Expression Word Problem

[msimard8]

In a motorcycle race, one lap of the course is 650m. At the start of the race, Genna sets off 4 seconds after Tom does, but she drives her motorcycle 5m/s faster and finishes the lap 2.5 seconds sooner than he does.

a) Find the speed at which each of them is driving.

b) Find the tim etaken by each of them to cover the distance.
How I started this problem

Let x be Genna's time if she started at the same time

Genna
time =x
distance =650
speed = 650/x

Tom

time = x +2.5
distance =650 m
speed = x +2.5

then i did 650/x - 650/x+2.5 = 5m/s

this generated the wrong answers

here are the correct answers

a)Tom 20m/s Genna 25.0m/s
b) Tom 32.5 s Genna 6s

Help

thanks

 

[Hootenanny]

You forgot to take into account that Genna started 4 seconds after Tom. Also Tom's speed is not given by;

speed = x +2.5

~H