All Courses
Explore Courses UPSC Exam UPSC Test Series Free Notes EduRev Infinity Get the App Login Join for Free
Sign in Open App
GMAT Exam  >  GMAT Questions  >  On Monday, Lou drives his ford escort with 28... Start Learning for Free
SaveJoin the Discussion on the App
On Monday, Lou drives his ford escort with 28-inch tires, averaging x miles per hour. On Tuesday, Lou
switches the tires on his car to 32-inch tires yet drives to work at the same average speed as on Monday. What is the percent change from Monday to Tuesday in the average number of revolutions that Lou’s tires make per second?
  • a)
    Decrease by 14.3%
  • b)
    Decrease by 12.5%
  • c)
    Increase by 14.3%
  • d)
    Increase by 12.5%
  • e)
    cannot be determined with the given information
Correct answer is option 'B'. Can you explain this answer?
FREE This question is part of
Download PDF Attempt Test
Download PDF Attempt this Test
Verified Answer
On Monday, Lou drives his ford escort with 28-inch tires, averaging x ...
The key to solving this question lies in understanding the mathematical relationship that exists between the speed (s), the circumference of the tires (c) and the number of revolutions the tires make per second (r).  It makes sense that if you keep the speed of the car the same but increase the size of the tires, the number of revolutions that the new tires make per second should go down.  What, however, is the exact relationship?
Sometimes the best way to come up with a formula expressing the relationship between different variables is to analyze the labels (or units) that are associated with those variables.  Let’s use the following units for the variables in this question (even though they are slightly different in the question):
      c: inches/revolution   
      s: inches/sec
      r: revolutions/sec
The labels suggest:  (rev/sec) x (inches/rev) = (inches/sec), which means that rc = s. 
When the speed is held constant, as it is in this question, the relationship rc = s becomes rc = k.  r and c are inversely proportional to one another.  When two variables are inversely proportional, it means that whatever factor you multiply one of the variables by, the other one changes by the inverse of that factor.  For example if you keep the speed constant and you double the circumference of the tires, the rev/sec will be halved.  In this way the product of c and r is kept constant.    
In this question the circumferences of the tires are given in inches, the speed in miles per hour, and the rotational speed in revolutions per second.  However, the discrepancies here don’t affect the fundamental mathematical relationship of inverse proportionality: if the speed is kept constant, the rev/sec of the tires will change in an inverse manner to the circumference of the tires.    
Let’s assign     c1 = initial circumference; c2 = new circumference
r1 = initial rev/sec ; r2 = new rev/sec
Since the speeds are held constant:
c1r1 = c2r2
r2 = (c1/c2)r1
r2 = (28/32)r1  
r2 = (7/8)r1
If the new rev/sec is 7/8 of the previous rev/sec, this represents a 1/8 or 12.5% decrease and the correct answer is (B).  Relationships of inverse proportionality are important in any word problem on the GMAT involving a formula in the form of xy = z and in which z is held constant. 
View all questions of this test
Most Upvoted Answer
On Monday, Lou drives his ford escort with 28-inch tires, averaging x ...
To solve this problem, we need to consider the relationship between the distance traveled and the number of revolutions.

The distance traveled is directly proportional to the number of revolutions. This means that if the distance traveled remains the same, the number of revolutions will also remain the same.

Since Lou drives to work at the same average speed on both Monday and Tuesday, the distance traveled will remain the same. Therefore, the number of revolutions will also remain the same.

This means that there is no percent change from Monday to Tuesday in the average number of revolutions. It remains constant at 100%.
Attention GMAT Students!
To make sure you are not studying endlessly, EduRev has designed GMAT study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in GMAT.
< Previous Question Next Question >
Explore Courses for GMAT exam

Similar GMAT Doubts

Climatic conditions are delicately adjusted to the composition of the Earth’s atmosphere. If there were a change in the atmosphere—for example, in the relative proportions of atmospheric gases—the climate would probably change also. A slight increase in water vapor, for instance, would increase the heat-retaining capacity of the atmosphere and would lead to a rise in global temperatures. In contrast, a large increase in water vapor would increase the thickness and extent of the cloud layer, reducing the amount of solar energy reaching the Earth’s surface.The level of carbon dioxide, CO2, in the atmosphere has an important effect on climatic change. Most of the Earth’s incoming energy is short-wavelength radiation, which tends to pass through atmospheric CO2 easily. The Earth, however, reradiates much of the received energy as long-wavelength radiation, which CO2 absorbs and then remits toward the Earth. This phenomenon, known as the greenhouse effect, can result in an increase in the surface temperature of a planet. An extreme example of the effect is shown by Venus, a planet covered by heavy clouds composed mostly of CO2, whose surface temperatures have been measured at 430. If the CO2 content of the atmosphere is reduced, the temperature falls. According to one respectable theory, if the atmospheric CO2 concentration were halved, the Earth would become completely covered with ice. Another equally respectable theory, however, states that a halving of the CO2 concentration would lead only to a reduction in global temperatures of 3.If, because of an increase in forest fires or volcanic activity, the CO2 content of the atmosphere increased, a warmer climate would be produced. Plant growth, which relies on both the warmth and the availability of CO2 would probably increase. As a consequence, plants would use more and more CO2. Eventually CO2 levels would diminish and the climate, in turn, would become cooler. With reduced temperatures many plants would die; CO2 would thereby be returned to the atmosphere and gradually the temperature would rise again. Thus, if this process occurred, there might be a long-term oscillation in the amount of CO2 present in the atmosphere, with regular temperature increases and decreases of a set magnitude.Some climatologists argue that the burning of fossil fuels has raised the level of CO2 in the atmosphere and has caused a global temperature increase of at least 1. But a supposed global temperature rise of 1 may in reality be only several regional temperature increases, restricted to areas where there are many meteorological stations and caused simply by shifts in the pattern of atmospheric circulation. Other areas, for example the Southern Hemisphere oceanic zone, may be experiencing an equivalent temperature decrease that is unrecognized because of the shortage of meteorological recording stations.The passage supplies information for answering which of the following questions?

merican economists continually attempt to gauge the health of the economy, both for the gain of the private sector as well as for the global standing of the United States. Different elements of the economy react differently to changes in prosperity. Some elements rise and fall as the economy waxes and wanes. These are known as coincident indicators. Other elements are known as leading indicators and usually show a downturn before the economy does. A third group of elements are known as lagging indicators and lose vigor only after the economy has already begun to slow. Economists can predict the direction of the economy by monitoring these indicators.Coincident indicators, such as manufacturing and employment rates, are the best gauge of the current state of the economy. A continued shift in these indicators allows economists to determine whether the economy itself is in the process of an upturn or a downturn. These indicators coincide with shifts in the economy because they are dependent on sustained prosperity. But since coincident indicators reflect only the current state of the economy, they are not especially useful in predicting how the economy will perform in the near future. Economists must look to other indicators for that.The indicators with the greatest predictive power are leading indicators, such as mortgage applications and profit margins. When these indicators rise or fall, economists can often foretell similar changes in the country’s economic health. These indicators do not cause changes in the economy. Rather, they often signal changes in economic behavior that lead to shifts in the economic cycle. By contrast, the third type of indicator – lagging indicators – is useless as a harbinger of change. But these indicators can be helpful in confirming the assessments of economists.Determining which elements of the economy fall into which category of indicator requires analysis of copious data and an understanding of the factors that propel the economy. One must determine which events surrounding a turn in the business cycle actually contributed to the change. Establishing a solid framework for understanding the behavior of these indicators helps economists to avoid miscalculations and to guide the country through periods of slow or negative economic growth.Q.The information in the passage suggests that which of the following would most strongly indicate an imminent change in the business cycle?

Climatic conditions are delicately adjusted to the composition of the Earth’s atmosphere. If there were a change in the atmosphere—for example, in the relative proportions of atmospheric gases—the climate would probably change also. A slight increase in water vapor, for instance, would increase the heat-retaining capacity of the atmosphere and would lead to a rise in global temperatures. In contrast, a large increase in water vapor would increase the thickness and extent of the cloud layer, reducing the amount of solar energy reaching the Earth’s surface.The level of carbon dioxide, CO2, in the atmosphere has an important effect on climatic change. Most of the Earth’s incoming energy is short-wavelength radiation, which tends to pass through atmospheric CO2 easily. The Earth, however, reradiates much of the received energy as long-wavelength radiation, which CO2 absorbs and then remits toward the Earth. This phenomenon, known as the greenhouse effect, can result in an increase in the surface temperature of a planet. An extreme example of the effect is shown by Venus, a planet covered by heavy clouds composed mostly of CO2, whose surface temperatures have been measured at 430. If the CO2 content of the atmosphere is reduced, the temperature falls. According to one respectable theory, if the atmospheric CO2 concentration were halved, the Earth would become completely covered with ice. Another equally respectable theory, however, states that a halving of the CO2 concentration would lead only to a reduction in global temperatures of 3.If, because of an increase in forest fires or volcanic activity, the CO2 content of the atmosphere increased, a warmer climate would be produced. Plant growth, which relies on both the warmth and the availability of CO2 would probably increase. As a consequence, plants would use more and more CO2. Eventually CO2 levels would diminish and the climate, in turn, would become cooler. With reduced temperatures many plants would die; CO2 would thereby be returned to the atmosphere and gradually the temperature would rise again. Thus, if this process occurred, there might be a long-term oscillation in the amount of CO2 present in the atmosphere, with regular temperature increases and decreases of a set magnitude.Some climatologists argue that the burning of fossil fuels has raised the level of CO2 in the atmosphere and has caused a global temperature increase of at least 1. But a supposed global temperature rise of 1 may in reality be only several regional temperature increases, restricted to areas where there are many meteorological stations and caused simply by shifts in the pattern of atmospheric circulation. Other areas, for example the Southern Hemisphere oceanic zone, may be experiencing an equivalent temperature decrease that is unrecognized because of the shortage of meteorological recording stations.The passage suggests that a large decrease in the amount of CO2 in the atmosphere would result in

The table below gives information for the year 2010 on the ridership in 9 subway stations in New York City. The subway stations were chosen for inclusion in the table because they were the busiest stations in 2010, based on the number of passengers entering the station. In addition to annual ridership (number of passengers) for each station in 2010, the table also gives the percent increase or decrease in ridership from 2009 to 2010 and the number of subway lines that connect to the station.Each column of the table can be sorted in ascending order by clicking on the word “Select” above the table and choosing, from the dropdown menu, the heading of the column on which you want the table to be sorted.Alternate Sort 1: % ChangeAlternate Sort 2: Connecting Subway LinesConsider each of the following statements about this Presidential election data. For each statement indicate whether the statement is true or false, based on the information provided in the table.Q.The station with the median rank based on annualridership is also the station with the greatest decreasein annual ridership from 2009 to 2010.

Top Courses for GMATView all

Top Courses for GMAT

On Monday, Lou drives his ford escort with 28-inch tires, averaging x miles per hour. On Tuesday, Louswitches the tires on his car to 32-inch tires yet drives to work at the same average speed as on Monday. What is the percent change from Monday to Tuesday in the average number of revolutions that Lou’s tires make per second?a)Decrease by 14.3%b)Decrease by 12.5%c)Increase by 14.3%d)Increase by 12.5%e)cannot be determined with the given informationCorrect answer is option 'B'. Can you explain this answer?
Question Description
On Monday, Lou drives his ford escort with 28-inch tires, averaging x miles per hour. On Tuesday, Louswitches the tires on his car to 32-inch tires yet drives to work at the same average speed as on Monday. What is the percent change from Monday to Tuesday in the average number of revolutions that Lou’s tires make per second?a)Decrease by 14.3%b)Decrease by 12.5%c)Increase by 14.3%d)Increase by 12.5%e)cannot be determined with the given informationCorrect answer is option 'B'. Can you explain this answer? for GMAT 2024 is part of GMAT preparation. The Question and answers have been prepared according to the GMAT exam syllabus. Information about On Monday, Lou drives his ford escort with 28-inch tires, averaging x miles per hour. On Tuesday, Louswitches the tires on his car to 32-inch tires yet drives to work at the same average speed as on Monday. What is the percent change from Monday to Tuesday in the average number of revolutions that Lou’s tires make per second?a)Decrease by 14.3%b)Decrease by 12.5%c)Increase by 14.3%d)Increase by 12.5%e)cannot be determined with the given informationCorrect answer is option 'B'. Can you explain this answer? covers all topics & solutions for GMAT 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for On Monday, Lou drives his ford escort with 28-inch tires, averaging x miles per hour. On Tuesday, Louswitches the tires on his car to 32-inch tires yet drives to work at the same average speed as on Monday. What is the percent change from Monday to Tuesday in the average number of revolutions that Lou’s tires make per second?a)Decrease by 14.3%b)Decrease by 12.5%c)Increase by 14.3%d)Increase by 12.5%e)cannot be determined with the given informationCorrect answer is option 'B'. Can you explain this answer?.
Solutions for On Monday, Lou drives his ford escort with 28-inch tires, averaging x miles per hour. On Tuesday, Louswitches the tires on his car to 32-inch tires yet drives to work at the same average speed as on Monday. What is the percent change from Monday to Tuesday in the average number of revolutions that Lou’s tires make per second?a)Decrease by 14.3%b)Decrease by 12.5%c)Increase by 14.3%d)Increase by 12.5%e)cannot be determined with the given informationCorrect answer is option 'B'. Can you explain this answer? in English & in Hindi are available as part of our courses for GMAT. Download more important topics, notes, lectures and mock test series for GMAT Exam by signing up for free.
Here you can find the meaning of On Monday, Lou drives his ford escort with 28-inch tires, averaging x miles per hour. On Tuesday, Louswitches the tires on his car to 32-inch tires yet drives to work at the same average speed as on Monday. What is the percent change from Monday to Tuesday in the average number of revolutions that Lou’s tires make per second?a)Decrease by 14.3%b)Decrease by 12.5%c)Increase by 14.3%d)Increase by 12.5%e)cannot be determined with the given informationCorrect answer is option 'B'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of On Monday, Lou drives his ford escort with 28-inch tires, averaging x miles per hour. On Tuesday, Louswitches the tires on his car to 32-inch tires yet drives to work at the same average speed as on Monday. What is the percent change from Monday to Tuesday in the average number of revolutions that Lou’s tires make per second?a)Decrease by 14.3%b)Decrease by 12.5%c)Increase by 14.3%d)Increase by 12.5%e)cannot be determined with the given informationCorrect answer is option 'B'. Can you explain this answer?, a detailed solution for On Monday, Lou drives his ford escort with 28-inch tires, averaging x miles per hour. On Tuesday, Louswitches the tires on his car to 32-inch tires yet drives to work at the same average speed as on Monday. What is the percent change from Monday to Tuesday in the average number of revolutions that Lou’s tires make per second?a)Decrease by 14.3%b)Decrease by 12.5%c)Increase by 14.3%d)Increase by 12.5%e)cannot be determined with the given informationCorrect answer is option 'B'. Can you explain this answer? has been provided alongside types of On Monday, Lou drives his ford escort with 28-inch tires, averaging x miles per hour. On Tuesday, Louswitches the tires on his car to 32-inch tires yet drives to work at the same average speed as on Monday. What is the percent change from Monday to Tuesday in the average number of revolutions that Lou’s tires make per second?a)Decrease by 14.3%b)Decrease by 12.5%c)Increase by 14.3%d)Increase by 12.5%e)cannot be determined with the given informationCorrect answer is option 'B'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice On Monday, Lou drives his ford escort with 28-inch tires, averaging x miles per hour. On Tuesday, Louswitches the tires on his car to 32-inch tires yet drives to work at the same average speed as on Monday. What is the percent change from Monday to Tuesday in the average number of revolutions that Lou’s tires make per second?a)Decrease by 14.3%b)Decrease by 12.5%c)Increase by 14.3%d)Increase by 12.5%e)cannot be determined with the given informationCorrect answer is option 'B'. Can you explain this answer? tests, examples and also practice GMAT tests.
Explore Courses for GMAT exam

Top Courses for GMAT

Explore Courses

Suggested Free Tests

Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev
Get App
© EduRev
Education Revolution
Signup to see your scores go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup