The last number will either be 5 or 0. For example 15, or 20.
To check if distances can be a triangle add the smaller two distances together. If the sum is larger (not equal to) than the longest distance then it is a possible side. For example, 2,2,4 or 1,2,5cannot be a triangle, 2,3, 4 can be a triangle because 2+3 is greater than 4.
There are 10 tons in 10,000 pounds because a 1,000 pounds makes 1 ton.
Answer:
20
Step-by-step explanation:

multiply both sides by 35

divide both sides by 35

To determine the number of cubes he needs to fill the box (this is assuming the cubes are 1 in cubes, he would need to calculate the volume of the box. To find the volume he would multiply the length by the width by the height. This would be 5 in x 6 in x 7 in. The volume is 210 cubic inches, so he could fill it with 210 one inch cubes.