<span>Say the code only needed to be one number long. Going from 0-9, there are ten digits. Therefore, there are ten unique codes.

Now say the code has to be two numbers long. There are ten possibilities for the first digit, 0-9. But the second digit only has nine possibilities, since each number has to be different. (The first number might be 0, so the second can only go from 1-9) For each of the first ten possibilities, there are nine possibilities for the second. We multiply those two numbers together, 10 * 9, and we get 90.

Now we just extend the logic. The third number only has eight possibilities, while the fourth number only has seven. 10 * 9 * 8 * 7 = 5040 possible codes. I hope this helped! has a great day! :)</span>

8 0

3 years ago

Why would using a net and needing to know how to calculate surface area be an important part of designing a three-dimensional ob

son4ous [18]

Answer:

A net is a pattern made when the surface of a three-dimensional figure or solid is laid out flat showing each face of the figure. It is then possible to use the net to calculate the surface area of the solid. Surface Area of a Cube using Nets. A cube is a three-dimensional figure with six matching square faces.

Step-by-step explanation:

hope it helps

4 0

4 years ago

consider a dianmeter of 8 feet and height of h feet.which equation can be used to find v,the volumeof the cylinder in cubic feet

yarga [219]

Answer:

diameter times height times x = volume

Step-by-step explanation:

using the length times width times height equation for volume.

good luck :)

4 0

4 years ago