This question was already asked so I will put the answer here.
The correct answer is letter (B) {1,2,3,4,...,163}.The burj khalifa the tallest building in the world with 163 floors, is having problems with is air conditioning system. It is suspected that thedifference is air pressure between the first floor and the top floor is the problem. normal pressure for the bottom floor is 14.7psi. a building engineer uses the function p to analyse pressure p(f) represents the pressure on each floor, where f is the floor number.
Let x be the amount (the volume in milliliters) of the 5% solution to be mixed.
Then the volume of the 1% solution is 100-x milliliters.
Then your "concentration" equation is
%280.01%2A%28100-x%29+%2B+0.05%2Ax%29%2F100 = 0.02,
or, equivalently,
100-x + 5*x = 200,
which implies
4x = 100 ----> x = 100%2Fx = 25.
Answer: 25 milliliters of the 5% solution must be mised with 100-25 = 75 milliliters of the 1% solution.
A)
First note that the plates can have between 4 and 6 symbols so we will need to find the number of plates with 4 symbols, 5 symbols and 6 symbols. We add these to get the total. In this part repetition of symbols is allowed. Since there are 26 + 10 =36 possible symbols we look at each position on the plate and think of how many choices there are. We multiply the number f choices using the counting principal since the choices are each independent -- one symbol does not affect another. There are 36 choices for the first symbol, 35 for the second and so on. The number of plates is:
4-symbols = (36)(36)(36)(36)=36^4
5 symbols = (36)^5
6 symbols = 36^6
So the total here is: 36^4+36^5+36^6
B) Here we do not repeat symbols so there are 36 choices for the first symbol but only 35 for the next and 34 for the one after and so on.
4-symbols = (36)(35)(34)(33)
5 symbols = (36)(35)(34)(33)(32)
6 symbols = (36)(35)(34)(33)(32)(31)
So the total here is: (36)(35)(34)(33)+(36)(35)(34)(33)(32)+(36)(35)(34)(33)(32)(31)
c)
In order for there to be a repeated symbol we have 36 choices for the first symbol, 36 for the next and so on. However, for the last symbol we have to pick from one of the ones already selected so there are 3, 4 or 5 choices respectively.
4-symbols = (36)(36)(36)(3)
5 symbols = (36)(36)(36)(36)(4)
6 symbols = (36)(36)(36)(36)(36)(5)
So the total here is: (36^3)(3)+(36^4)(4)+(36^5)(5)
D)
The probability is given by (the number of plates with at least one repeated symbol)/(the total number of plates if repetitions are allowed) = (the answer to c) / (the answer to a)
I think the equation is y= -1/3x+1. The slope is going down, so it’s negative. And the y intercept is 1. And how I got a fraction is by using rise/run.
Where is this system please ?
