Question 1059638
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The first car is going 40 mi/h,and the second car is going 55 mi/h.the first car left 3 hours before the second car.
what equation could you use to find how many hours it will take for the second car to catch up to the first car?
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Everything is in these 4 lines below.


<pre>
Time to catch = {{{(3*40)/(55-40)}}} = {{{120/15}}} = 8 hours.

The numerator 3*40 = 120 kilometers is the distance for the first car to be ahead at the moment the second car started.


The difference (55-40) in the denominator is the rate of decreasing the distance between two cars. 
It is their relative speed.


That's all.
</pre>

You should be able to write such an equation instantly as you read and understand the problem.


Producing tables is not the way solving such problems.