Question

Melissa is painting vertical stripes on one of the walls in her bedroom. The number of stripes, s, she can paint on the wall varies inversely as the distance, d, between each stripe varies. If she can paint 20 stripes on the wall when the distance between each stripe is 6 inches, about how many stripes can she paint on the wall if the distance between each stripe is 9 inches?

Answer 1

Answer: 13 strips ( Approx )

Explanation:

Here, s represents the number of strips and d represents the distance between each strips.

According to the question,

's' is inversely proportional to 'd',

⇒
`s \propto (1)/(d)`

⇒
`s = (k)/(d)` ---------(1)

Where k is the constant of proportionality,

Since, she can paint 20 stripes on the wall when the distance between each stripe is 6 inches,

⇒ For s = 20, d = 6 inches

By substituting these values in equation (1),

We get,

`20 = (k)/(6)`

`120 = k`

Now, Substituting the value of k in equation (1),

The equation that shows the relation between s and k,

⇒
`s = (120)/(d)`

For, d = 9,

`s = (120)/(9)=13.\bar{3}\approx 13`

Hence, when the difference between each strip is 9 inches she can paint approx 13 strips.