Question: Marty has 100 centimeters of ribbon that he must cut into 4 equal parts. Each of the cut parts must be divided into 5 equal parts. How long will each final cut be?
Give me a solution to this problem
Answer: 
The 100-centimeter ribbon is cut into 4 equal parts in pieces of 100 / 4 = 25 cm
From each piece of 25 cm, he gets 5 equal parts of 25 / 5 = 5 cm each.