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Question 530120: Can you please answer this question: There were x people on a bus when it left A. It then stopped only at B,C,D. At B 5 people got on and nobody got off. After leaving C, there was three times as many people on the bus as when it arrived there. There were 42 people on the bus when it arrived in D. I have to form an equation in x and solve it to find the number of people on the bus when it left. A. Thank you for your time.
Answer by KMST(5328)   (Show Source):
You can put this solution on YOUR website! When the bus left A there were x people on it.
At B 5 people got on and nobody got off, so as the bus left B, there were
x+5 people on it.
Unless someone jumped out of the window en route, there were x+5 people on the bus when it arrived at C.
As the bus left C, the number of people was 3 times as many as the x+5 people on the bus when it reached C.
That's  people on the bus as it left C.
Unless someone jumped out of the window en route, there was the same number of people when the bus reached D. So,
 or 
You could solve either equation.
For example, if
dividing by 3 both sides, tells you that 
and subtracting 5 from both sides tells you that  .
Keep in mind that algebra was not really needed to solve this problem. Sometimes, however, situations are so complicated that we want to resort to algebra. (And sometimes the teachers make us do it).
Here's the solution with just 4th grade thinking smarts.
The number of people on the bus when it left C to go to D was 42.
You know that is 3 time as many people as were on the bus when it reached C. So there were 14 people on the bus when it reached C, and those were the people on the bus when it left B. Subtract the 5 people that got on the bus at B and you have the original 9 passengers.
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