a 4-foot-wide bookshelf contains 20 books. how much room is left on the
bookshelf if 10 of the books are 1-inch wide and 10 of the books are 1.25 inches
wide?

2.125ft

Step-by-step explanation:

10×1=10

10×1.25= 12.5

12.5+10= 22.5in

22.5 in = 1.875ft

4-1.875= 2.125ft left

Step-by-step explanation:

I foot = 12 inches

1 inch = 1/12 foot

If the books are 1.-inch wide, converting to foot, it becomes 1/12 foot wide. It means that the total space occupied by 10 books of this size is

10 × 1/12 = 10/12 = 0.833 foot.

If the books are 1.25-inch wide, converting to foot, it becomes 1/12 × 1.25 = foot wide. It means that the total space occupied by 10 books of this size is

10 × 1/12 × 1.25 = 12.5/12 = 1.042 foot.

Total space occupied by the books would be

0.833 + 1.042 = 1.875 feet

Amount of room left in the bookshelf would be

4 - 1.875 = 2.125 feet

3: 2

step-by-step explanation:

shorter piece is 2: 3, so just reverse it, and you get 3: 2