Please help! Question about rounding?

[CHIAYU]

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

A) 290/12.5 and 290/11.4
B) 295/12 and 284/11.4
C) 284/12 and 295/12
D) 284/12.5 and 295/11.4 ( answer is D)
E) 295/12.5 and 284/11.4

The OG explains that since the miles are rounded to the nearest 10 miles, they can range anywhere from 284 miles to 295 miles. I'm wondering why 284 can be rounded up to 290, and 295 can be rounded down to 290?

The OG also explains that since the gallons of gasoline are rounded to the nearest gallon, they can range anywhere from 11.4 to 12.5 gallon. I'm also wondering why 11.4 can be rounded up to 12, and 12.5 can be rounded down to 12?

Thanks for any help. I really appreciate it

[Carol]

My approach:


the miles are rounded to the nearest 10 miles - so we should have to take the ten digit in consideration, not the unit digit - so the values will range between these 2.

you see what happened to 12 gallons , you added the decimal digit...the nearest gallon is what matters here!

and the question is: The actual number of miles per gallon that Cindy's car got on this trip must have been between
284/12.5 and 295/11.4

[vittalgmat]

Hi
I think that the range for rounding should be 285 - 294 and
11.5 - 12.4

thanks
-Vittal

[vittalgmat]

Hi
I think that the range for rounding should be 285 - 294 and
11.5 - 12.4

thanks
-Vittal