To solve for the rate of the second bus (\(r\)), we can use the equation provided:
\[ 3(r + 10) + 3r = 282 \]
First, simplify the equation:
\[ 3r + 30 + 3r = 282 \]
Combine like terms:
\[ 6r + 30 = 282 \]
Next, subtract 30 from both sides:
\[ 6r = 252 \]
Now, divide both sides by 6:
\[ r = 42 \]
So, the rate of the second bus is \( \text{r = 42 mph} \).
The correct response is:
r = 42 mph