Let the total ribbon Zoe had was x feet.
Out of x feet, she used 3/8 part of it.
Hence, 
3/8 part of the original ribbon is equal to 9 feet.
Hence, we get

=> Multiply 8 on both sides.

Divide both sides by 3


Zoe had 24 feet of ribbon in starting... Answer
Answer:
28 questions
Step-by-step explanation:
In the first 10 mins she answered 2/5 of 40 which is 16. The remaining amount is 24 questions and half of that is 12. So she answered 12 questions in 15 mins. Finally you add them to get 28 questions in 25 minutes.
Answer:
118,692
Step-by-step explanation: