In order to finance road repairs, the highway commission of a certain

(E) The total distance traveled by vehicles on the toll highway per year will not decrease from its current level.

The stimulus says
he highway commission of a certain state is considering a 50 percent increase in the 10-centers-per-mile toll for vehicles using its toll highway.

Conclusion is
the toll increase will increase the annual revenue generated by the toll highway by at least 50 percent per year.

so the percentage of increase in toll = percentage of increase in revenue
i.e total distance traveled on the bridge is constant. its the total distance because the toll is calculated on per mile basis. not the number of trips or average length of the trips or the number of travelers on the bridge

So the ans is E

In (C) you said, "What if the number of trips goes down? Then the total distance will go down." Then in (D) you said that the number of trips is "out of scope." You contradicted yourself and helped explain why (D) is also correct.

Honestly, I guess I understand why (E) is the OA - because it's the only one that specifically mentions the total distance traveled - but B and D will also directly lead to a decrease in the total number of miles traveled. It seems really ambiguous to me.

Total distance travelled needs to be constant inorder to 50% increase in revenue. So E.

This was a good question. I got confused between B & E.. And its obvious to get confused here either of the ways revenue will decrease. But as the answer states, the key here is 50% increase..

This is not a DS question. In option C, by telling us about the average length of trip and not about the number of trips and in D, by telling us about the number of trips and not about the average length, we are left with incomplete information. I don't see any contradiction.


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Profit = revenue - cost.
So, in order for profit to increase, revenue will need to increase and, cost must decrease OR remain unchanged.
E, states that, the total distance traveled by the trucks should not decrease/unchanged....if it decreases then, the trucks may take a shorter route and not end-up paying toll. Therefore, the commissioner assumes that "total distance" will not change causing any effect on the profit.

Friends we overlooke dthe purpose behind why this questions has been posted in the First Place.
The Guy who posted this question is confused because he finds all the options correct except A and i agree with Him.
I feel all the options except A make it appear that the Revenue will decrease if any of the options B to E are implemented.
Guys please correct me if we are wrong .
I suppose Teh Jay agrees on this view

The question is fairly straightforward. A 50% increase in the per-mile toll is brought about. In order to increase the annual revenue, the mandated condition is: Number of miles remain same, or increases.

In order to finance road repairs, the highway commission of a certain state is considering a 50 percent increase in the 10-centers-per-mile toll for vehicles using its toll highway. The highway commissioner claims that the toll increase will increase the annual revenue generated by the toll highway by at least 50 percent per year.

Which of the following is an assumption on which the highway commissioner's claim depends?

(A) The amount of money required annually for road repairs will not increase from its current level. - Irrelevant. Why do we care about the road repairs? We are talking about revenue generated by tolls, not the "profit" or "breakeven" of the highway authorities.
(B) The total number of trips made on the toll highway per year will not decrease from its current level. - Information about number of trips without average mileage per trip is redundant.
(C) The average length of a trip made on the toll highway will not decrease from its current level. As stated above, information about mileage without the number of trips will not serve any purpose for what we are asked to find here.
(D) The number of drivers who consistently avoid the highway tolls by using secondary roads will not increase from its current level. This is a very indirect option, and we can probably hold on to see if there's a better answer.
(E) The total distance traveled by vehicles on the toll highway per year will not decrease from its current level. This is the correct answer. If you are looking a toll that is charged per mile, and you know the total distance traveled by the cars stays the same, in essence you're saying that there's a 50% increase in the revenues. Think about numerical figures:

Let's say total distance traveled before was 100 miles. This stays the same now. Let's assume the toll per mile was $1 initially and now it's $1.5. Original revenue was $100 and now revenue is $150, which is 50% more than the original revenue. This statement directly supplements the question and hence is the right choice.


TehJay's Question was:

B and D give you one part of the information and fail to give you the rest. Knowledge about the number of trips without average distance traveled per trip or vice versa is not useful in evaluating this argument. Okay, as per B the number of trips has increased from say, 50 to 100. But the average length of the trip has gone down from 3 miles to 1 mile, this means, in effect, the toll collected has reduced. Similarly for the other situation. Let's say the average miles per trip has gone up, but it's in a way that the number of trips have gone down. So each piece by itself is insufficient to frame a conclusion. You can't afford to assume whatever you need to justify an answer or in this case, answers that seems right. Thinking objectively about all possible constraints will help resolve most issues on tricky questions like these. And in the end, sometimes, you just have to go with the best option, since it might feel like multiple options are correct sometimes.

Yea Thanks for the explanation.

'Thinking objectively about all possible constraints will help resolve most issues on tricky questions like these.'
thanks whiplash
that is a very good practice .all possible constraints have to be considered. this was definitely a tricky question,

Lol I couldn't understand what "centers per mile toll" meant until i read the answers.

When i first read that, i couldn't make any sense of the line that there will be a 50% increase in 10 centers-per-mile roll. I was picturing 10 toll centers every mile lol.

We know revenue is price x quantity .

In our case: Revenue = cost per mile x total number of miles
Let cost per mile = p
and total miles = q

So R = p*q.....(equation 1)
With a 50% increase in p, we want the total revenue to also increase by at least 50%.
Thus 1.5R >= 1.5p*q.....(equation 2) -> Conclusion

Thus for equation 2 to hold, the total number of miles must remain the same or increase...i.e they should not decrease
So any choice that talks about total number of miles ought be the right choice

Answer option E

None of the other choices talk about total miles. They play around with something decreasing...but not the total miles

I am not able to understand what is "10-centers-per-mile toll"? Can someone explain. In light of the answer, it should be "10-cents-per-mile toll"

Should the definition of Revenue known before solving this question? I really had to consider the definition I knew of collecting toll in my country.
Definition: Revenue = Number of times a vehicle passes through the toll gate*ticket cost for each time it passes. Based on this definition, I ended up selecting the obvious second best choice B. Honestly, I don't think the toll collection definition can depend on the number of miles in any other country. I might be wrong but that is pretty basic.

This is slightly demotivating as it is an official question.

I think it should be 10 cents per mile

Hopefully that should clarify my doubt too: