Question

A set of eight built-in bookshelves is to be constructed in a room. The floor-to-ceiling clearance is 7 ft 5 in. Each shelf is 1 in. thick. An equal space is to be left between the shelves, the top shelf and the ceiling, and the bottom shelf and the floor. How many inches should there be between each shelf and the next? (There is no shelf against the ceiling and no shelf on the floor.)

Answer 1

Explanation:

The floor-to-ceiling clearance is 7 ft 5 in, which is equal to 7 * 12 + 5 = 89 inches.

We need to construct 8 shelves, each of which is 1 inch thick, so the total thickness of the shelves is 8 * 1 = 8 inches.

We also need to leave an equal space between each shelf and the next, the top shelf and the ceiling, and the bottom shelf and the floor. So, there will be 7 equal spaces in total (6 between shelves and 1 between the bottom shelf and the floor).

Therefore, the space between each shelf and the next will be (89 - 8) / 7 = 11 inches.

Here's a step by step solution:

Calculate the total height of the room in inches: 7 ft 5 in = 7 * 12 + 5 = 89 inches.

Calculate the total thickness of all the shelves: 8 shelves * 1 inch/shelf = 8 inches.

Deduct the thickness of the shelves from the height of the room to find the total space available: 89 inches - 8 inches = 81 inches.

Divide the total space available by the number of spaces (7) to find the space between each shelf and the next: 81 inches / 7 = 11 inches.