I believe the answer is 48 ... hope this helps
The 24 inch shelve is 2 feet ( 1 foot = 12 inches)
She bout 7 feet of shelves (5 + 2 = 7)
The total cost for the shelves was 7 x 1.25 = $8.75
She spend an additional 90 so her total spent was 90 + 8.75 = $98.75
Now subtract her total from 100 to find the amount of change:
100 - 98.75 = 1.25
The change was $1.25
Answer 1a 18 1b 36 1c 648
1a : if you look at the shape you will see its made of squares. I counted the squares, its 18.
1b : one side is 6 in. since its a square all sides are equal. so multiply 6 by 6 to get 36.
1c : this one is easy. We take the number of squares across the surface (18) by the area of each square (36) it is 648.
Also sorry I didn't make this clearer earlier.
Three yard piece for 16.11! Hope this helps