Re: The ratio of buses to cars on River Road is 2 to 23. If
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30 Aug 2020, 23:56
Let \(b\) and \(c\) be the numbers of buses and cars, respectively.
We have \(b:c = 2:23\) or \(2c = 23b\), which is equivalent to \(b = \frac{2}{23}c\).
In addition, we have \(c = b + 630\).
When we replace \(b\) by \(\frac{2}{23}c\) in the last equation, we have \(c = \frac{2}{23}c + 630\) or \(\frac{21}{23}c = 630\).
Then we have \(c = \frac{23}{21} \cdot 630 = 690\).
Therefore, D is the right answer.