At Rosa's Rose Shop, a bouquet containing a dozen roses costs $20. If the price of a bouquet is directly proportional to the number of roses it contains, how many dollars will a bouquet of 39 roses cost?

x/39 = 20/12

To find out how many dollars a bouquet of 39 roses will cost, we can set up a proportion using the given information.

Let "x" be the cost of a bouquet of 39 roses.

We know that the price of a bouquet is directly proportional to the number of roses it contains. Since a bouquet of 12 roses costs $20, we can write the proportion as:

12/20 = 39/x

To solve for "x", we can cross multiply:

12 * x = 20 * 39

12x = 780

Now, let's isolate "x" by dividing both sides by 12:

x = 780 / 12

x ≈ 65

Therefore, a bouquet of 39 roses will cost approximately $65.

To find out how many dollars a bouquet of 39 roses will cost, we need to determine the constant of proportionality that relates the number of roses to the price.

Given that a bouquet containing a dozen roses costs $20, we can set up a proportion to find the constant of proportionality:

(12 roses/$20) = (39 roses/x)

By cross-multiplying, we get:

12x = 39 * $20

Simplifying the equation, we have:

12x = $780

Dividing both sides by 12, we find:

x = $780/12

Evaluating the expression, we get:

x ≈ $65

Therefore, a bouquet of 39 roses will cost approximately $65.