Question

Small cubes with edge lengths of 1/4 inch will be packed into the right rectangular prism. The dimensions are 4 1/2 inches in length, 5 inches in width, and 3 3/4 inches in height. Each cube is 1/4 inches. How many small cubes are needed to completely fill the right rectangular prism? I have been trying to figure this problem out for over 3 hours. I know the answer is 5400,but I have no Idea of how to do the problem. I've tried every possibility that I could think of. Please help me. I'm so frustrated. Thank you

Answer 1

Let's see how many cubes we can lay along the length,
4.5 ÷ .25 = 18
and along the width,
5 ÷ .25 = 20
and how high can we stock them?
3.75 ÷ .25 = 15

So there would be 18 x 20 x 15 of them or 5400

(and you spent 3 hours on this? not possible!)

another way:
volume of 1 cube = .25^3 = .015625
volume box = (4.5)(5)(3.75) = 84.375

number of cubes = 84.375/.015625 = 5400

Answer 2

Thanks for the help!

Answer 3

5+5=10