First, you need to find out how much ribbon she has total. Because there are two spools, you multiply 24 x 2. The answer for that is 48. Then you have to figure out how many bows she can make. Each bow uses 1/8 of a piece of yard of ribbon, so you can divide 48 by 8. Your answer would then be 6 bows.
Here are the equations.
24*2 = X
X/8 = B
Where X represents the yards of ribbon available and B represents the number of bows that Mari can make.
