Question

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. $\frac{290}{12.5}$ and $\frac{290}{11.5}$
• B. $\frac{295}{12}$ and $\frac{285}{11.5}$
• C. $\frac{285}{12}$ and $\frac{295}{12}$
• D. $\frac{285}{12.5}$ and $\frac{295}{11.5}$
• E. $\frac{295}{12.5}$ and $\frac{285}{11.5}$

Answer 1

The correct option is D $\frac{285}{12.5}$ and $\frac{295}{11.5}$

Here, the rounding off of numbers is tested.

Distance rounded to nearest 10 miles = 290.

So actual distance covered may be b/w 285 and 295.

Gasoline used rounded to nearest gallon = 12.

So the actual gas used may be b/w 11.5 and 12.5.

Now to get range of of miles/gallon,

least value = the least of distance/the max of gas = 285/12.5

highest value = max of distance/least of gas = 295/11.5

Option D is the correct choice.