Answer:
= a(b+c)
Step-by-step explanation:
you can factorize out the a
The answer would be 7.81, or about 8 units if you estimate
Answer:
See below in bold.
Step-by-step explanation:
Mean = 150 cm = 150 * 0.033 feet
= 4.95 feet.
The standard deviation = 10 cm = 10 * 0.033
= 0.33 feet.
Answer: The expected waiting time is 
Step-by-step explanation:
Since we have given that
Average waiting time for slow elevator = 3 min
Average waiting time for fast elevator = 1 min
probability that a person choose the fast elevator = 
Probability that a person choose the slow elevator = 
So, the expected waiting time would be
![E[x]=\sum xp(x)=3\times \dfrac{1}{3}+1\times \dfrac{2}{3}\\\\=1+\dfrac{2}{3}\\\\=\dfrac{3+2}{3}\\\\=\dfrac{5}{3}\\\\=1\dfrac{2}{3}\ min](https://tex.z-dn.net/?f=E%5Bx%5D%3D%5Csum%20xp%28x%29%3D3%5Ctimes%20%5Cdfrac%7B1%7D%7B3%7D%2B1%5Ctimes%20%5Cdfrac%7B2%7D%7B3%7D%5C%5C%5C%5C%3D1%2B%5Cdfrac%7B2%7D%7B3%7D%5C%5C%5C%5C%3D%5Cdfrac%7B3%2B2%7D%7B3%7D%5C%5C%5C%5C%3D%5Cdfrac%7B5%7D%7B3%7D%5C%5C%5C%5C%3D1%5Cdfrac%7B2%7D%7B3%7D%5C%20min)
Hence, the expected waiting time is
Answer:
a + b = 5
Step-by-step explanation:
To solve this system of equations, we can use a strategy called elimination, which is when we get rid of a variable by adding/subtracting two equations.
Firstly, we want to make sure the absolute value of the coefficients that equal.
Lets eliminate b:
4a + 6b = 24
Multiply both sides by 2:
8a + 12b = 48
We also have:
6a - 12b = -6.
Now lets add that with
8a + 12b = 48
-> 6a + 8a + 12b - 12b = 48 -6
-> 14a = 42
-> a = 3
Now that we know a, lets plug it into one of our original equations:
4(3) + 6b = 24
12 + 6b = 24
6b = 12
b = 2
Finally, add the two values we found:
a+b = 2+3= 5
