Mary bought a roll of ribbon. After using 5/8 of the ribbon to decorate some packages she had 15ft left how many feet of ribbon did she buy

(3/8)x = 15

Solve for x.

To find out how many feet of ribbon Mary bought, we can use the information given. Let's break it down step by step:

1. Mary used 5/8 of the ribbon to decorate some packages.
2. After using 5/8 of the ribbon, she had 15ft left.

To calculate the amount she used, subtract what is left from what was originally purchased. Since she used 5/8 of the ribbon, the amount left would be 3/8 of the original amount.

Let's represent the amount of ribbon Mary bought as "x".

So, we can set up an equation:

x - (3/8)x = 15

To solve for "x," we can simplify the equation:

(5/8)x = 15

Next, we can solve for "x" by multiplying both sides of the equation by the reciprocal of (5/8):

[(8/5)*(5/8)] * x = 15 * (8/5)

1 * x = (120)/5

x = 120/5

By dividing 120 by 5, we find that:

x = 24

Therefore, Mary initially bought 24 feet of ribbon.