Answer:
its 19. 60 just add it three more times and that is your answer
Answer:
The probability that the household has only cell phones and has high-speed Internet is 0.408
Step-by-step explanation:
Let A be the event that represents U.S. households has only cell phones
Let B be the event that represents U.S. households have high-speed Internet.
We are given that 51% of U.S. households has only cell phones
P(A)=0.51
We are given that 70% of the U.S. households have high-speed Internet.
P(B)=0.7
We are given that U.S. households having only cell phones, 80% have high-speed Internet. A U.S household is randomly selected.
P(B|A)=0.8

Hence the probability that the household has only cell phones and has high-speed Internet is 0.408
Like all problems that involve images within the question, we should definitely try to draw this out. In the picture above, I have done this.
Now, we can see that this is just a simple proportion problem. For every 2.5 cm of height of the flower, we are 2 cm from the opening, or aperture. For every 20 cm of height, how far are we? We can set up the problem like this:
20 ............2.5
-------- = ---------
...x ............. 2
where x is the unknown distance to the aperture from the flower. Now, we just need to get x by itself. A typical way of solving something like this is by doing "butterfly multiplication" which is really just a shortcut haha. Anyway, I can rewrite that equation ^ as:
20×2 = 2.5 × x
Then, to solve for x, we would divide both sides by 2.5. (If you don't know why that is, please let me know and I'll elaborate).
We would then have:
20×2
------- = x
2.5
Which then simplifies to:
x = 16
Try using the same logic for your second question, and if you get stuck, I'd be happy to help! please let me know if any of this doesn't make sense. :)
This is rationalising the denominator of an imaginary fraction. We want to remove all i's from the denominator.
To do this, we multiply the fraction by 1. However 1 can be expressed in an infinite number of ways. For example, 1 = 2/2 = 3/3 = 4n^2 / 4n^2 (assuming n is not zero!). Let's express 1 as the complex conjugate of the denominator, divided by the complex conjugate of the denominator.
The complex conjugate of (3 - 2i) is (3 + 2i). Then do what I just said:
4/(3-2i) * (3+2i)/(3+2i) = 4(3+2i)/(3-2i)(3+2i) = (12+8i)/(9-4i^2) = (12+8i)/(9+4) = (12+8i)/13
This is the answer you are looking for. I hope this helps :)