5 percent is the difference between 10 and 5 because the ramp needs to be 5 percent but most average wheelchair ramps are 10 degrees and there is a 5 degree differance
One of the ramps is 5° and the other one is 10°. The difference between these 2 ramps is of 5°.
10 - 5 = 5
And as you can see in the image, the mid ray is what divided both of the other rays, and its right in the middle. Both rays combined gives you 10° as it shows, and half of 10 is 5. So the difference will be of 5°
Size 40 is the cheapest, because the formula to find lowest price of unit is dividing the price by the unit. so 5.49/24≈ 0.23, 8.00/40=0.2, 15.99/64≈ 0.25