Answer:
The ribbon was 310 inches long at first.
Explanation:
First, we will determine the length of ribbon that was cut.
From the question,
You cut a ribbon every 40 inches, that is, the length of each ribbon is 40 inches
Since, we have 7 pieces of ribbon, then total length of the ribbon that was cut will be
40 inches × 7
= 280 inches
This the total length of ribbon that was cut from the initial length of ribbon.
Now, after cutting 7 pieces of ribbon, there are 30 inches of ribbon left,
To determine how long the ribbon was at first,
we will sum the total length of ribbon that was cut from the initial length to the remaining length of ribbon after cutting, that is
280 inches + 30 inches
= 310 inches
This is the initial length of the ribbon.
Hence, the ribbon was 310 inches long at first.