1/4 * 1/3 * 1/2 * 1/1 = 1/24 chance that all 4 letters are placed in the correct envelopes.
With the first envelope, there are 4 choices of letters, so the probability of picking the correct letter is 1/4.
With the second envelope, there are 3 remaining letters, so the probability of picking the correct letter is 1/3.
The same logic follows the the third and final letter.
Ap is a line in the picture
Answer:
called unit rate .
Step-by-step explanation:
Answer:
2 hours: 3968 <u>[I don't understand the $ sign in the answer box]</u>
At midnight: 12137
Step-by-step explanation:
The bacteria are increasing by 15% every hour. So for every hour we will have what we started with, plus 15% more.
The "15% more" can be represented mathematically with (1 + 0.15) or 1.15. Let's call this the "growth factor" and assign it the variable b. b is (1 + percent increase).
Since this per hour, in 1 hour we'll have (3000)*(1.15) = 3450
At the end of the second hour we're increased by 15% again:
(3450)*(1.15) = 3968.
Each additional hour add another (1.15) factor, If we assign a to be the starting population, this can be represented by:
P = a(1.15)^t for this sample that increase 15% per hour. t is time, in hours.
If a represents the growth factor, and P is the total population, the general expression is
P = ab^t
Using this for a = 3000 and b = 1.15, we can find the total population at midnight after starting at 2PM. That is a 10 hour period, so t = 10
P = (3000)*(1.15)^10
P = 12137
Area of a triangle is equal to 1/2 b(h) so since you already have the height and base, all you need to do is input it back into the equation:

(10)(13)
Multiply 10 & 13 to equal

(130)
Then take half of 130 to get
A = 65