For a certain rectangular region, the ratio of its length to its width is 6 to 4. If the width of the rectangular region increases by 11 units, how must the length change to maintain this ratio?

Explanation:

The ratio of length and width is

Now the width increases by 11 units. Let the length be x units

The ratio of the sides will be the same for the new rectangle, so we get

The length of the new rectangle would be

Increase in length is .