If order matters, then there are 12 ways to do this
If order does not matter, then there are 6 ways to do this
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We have 4 choices for the first slot and 3 choices for the next (we can't reuse a letter) so that's where 4*3 = 12 comes from
If order doesn't matter, then something like AB is the same as BA. So we are doubly counting each possible combo. To fix this, we divide by 2: 12/2 = 6
To be more formal, you can use nPr and nCr to get 12 and 6 respectively (use n = 4 and r = 2)
The perimeter would be 12 and the area would be 6
The brick will fall to the ground after 9 secs.
<h3>What are quadratic equations?</h3>
Given the equation for height as a function of time is h(t) = -16t2 + 1,296
The height of the brick on the ground is h(t) = 0. Substitute h(t) = 0 into the equation as shown:
Subtract 1296 from both sides
-16t² + 1,296 - 1296 = 0 - 1296
16t² = 1296
t² = 1296/16
t² = 81
t = 9secs
Hence the brick will fall to the ground after 9 secs.
Learn more on equations here: brainly.com/question/13763238
5.07, the 4 is the thousands
