Respuesta :

recall your d = r*t  or distance = rate * time

so... let's say B is going at a speed of "r"
A is slower than B by 20mph, or whatever "r" is, A's speed is r - 20

at a certain time "t", A runs 230 miles whilst B runs 330 miles, same "t" time

so..  hmmm [tex]\bf \begin{array}{lccclll} &distance&rate&time\\ &-----&-----&-----\\ A&230&r-20&t\\ B&330&r&t \end{array}\\\\ -----------------------------\\\\ \begin{cases} 230=(r-20)(t)\\\\ 330=(r)(t)\implies \frac{330}{r}=\boxed{t}\\ ----------\\ 230=(r-20)\left( \boxed{\frac{330}{r}} \right) \end{cases}[/tex]

solve for "r", to see how fast B was going

what about A?  well,  A's speed is r - 20

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