Hi guys,
I decided to make a new thread regarding all the problems (from the problem solving part only) that I encounter throughout my preparation. So here is the first one. It concerns task 142 from the Official GMAT Review. The task
On a recent trip, Cindy drove her car 290 miles, rounded to the nearest 10 miles, and used 12 gallons of gasoline, rounded to the nearest gallon. The actual number of miles per gallon that Cindy's car got on this trip must have been between ?
My solution: Since the miles are rounded to the nearest 10 miles ==> the range of the mileage is from 285 to 294 (because 284 rounded to the nearest 10 would yield 280, and 295 would yield 300). The range of the fuel is between 11,5 and 12,4 (because 11,4 yields 11 gallon and 12,5 would yield 13 gallons).
Therefore the actual number of miles per galon must have been between 285/11,5 and 294/12,4.
However the Authors of the OG 13 give the answer: The range is between: 285/12,5 and 295/11,5.
How is this possible, since 12, 5 rounded to the nearest gallon would yield not 12 but rather 13. And 295 rounded to the nearest 10 would actually yield 300 ??
I decided to make a new thread regarding all the problems (from the problem solving part only) that I encounter throughout my preparation. So here is the first one. It concerns task 142 from the Official GMAT Review. The task
On a recent trip, Cindy drove her car 290 miles, rounded to the nearest 10 miles, and used 12 gallons of gasoline, rounded to the nearest gallon. The actual number of miles per gallon that Cindy's car got on this trip must have been between ?
My solution: Since the miles are rounded to the nearest 10 miles ==> the range of the mileage is from 285 to 294 (because 284 rounded to the nearest 10 would yield 280, and 295 would yield 300). The range of the fuel is between 11,5 and 12,4 (because 11,4 yields 11 gallon and 12,5 would yield 13 gallons).
Therefore the actual number of miles per galon must have been between 285/11,5 and 294/12,4.
However the Authors of the OG 13 give the answer: The range is between: 285/12,5 and 295/11,5.
How is this possible, since 12, 5 rounded to the nearest gallon would yield not 12 but rather 13. And 295 rounded to the nearest 10 would actually yield 300 ??
