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:
-5
Step-by-step explanation:
3x²y + xy²
Let x = -1/2 and y = 4
3(-1/2)^2 (4) + (-1/2) (4)^2
Exponents first
3(1/4) (4) + (-1/2) 16
Multiply
3 - 8
Subtract
-5
We already know that there are 12 sandwiches.
If there are 3 turkey and 5 veggie then there's 8 out of 12 sandwiches that aren't ham.
12 sandwiches - 8 non-ham sandwiches = 4 ham sandwiches
Now we know there are 4/12 ham sandwiches
We need to simplify this now.
4/12 can be divided by 4
4 goes into 4 1 time and 4 goes into 12 3 times making the answer 1/3
1/3 of the sandwiches are ham.
