Answer:
or 
Step-by-step explanation:
Given



Required
Determine the probability of selecting Black and Red
First, we need to calculate the number of red and black balls
The probability is calculated as thus:

Convert to mathematical expressions
![Probability = [P(Black) *P(Red)] + [P(Red) *P(Black)]](https://tex.z-dn.net/?f=Probability%20%3D%20%5BP%28Black%29%20%2AP%28Red%29%5D%20%2B%20%5BP%28Red%29%20%2AP%28Black%29%5D)
Solve for each probaility;


So, we have:
![Probability = [P(Black) *P(Red)] + [P(Red) *P(Black)]](https://tex.z-dn.net/?f=Probability%20%3D%20%5BP%28Black%29%20%2AP%28Red%29%5D%20%2B%20%5BP%28Red%29%20%2AP%28Black%29%5D)
![Probability = [\frac{25}{100} *\frac{40}{100}] + [\frac{40}{100} *\frac{25}{100}]](https://tex.z-dn.net/?f=Probability%20%3D%20%5B%5Cfrac%7B25%7D%7B100%7D%20%2A%5Cfrac%7B40%7D%7B100%7D%5D%20%2B%20%5B%5Cfrac%7B40%7D%7B100%7D%20%2A%5Cfrac%7B25%7D%7B100%7D%5D)
![Probability = [\frac{1000}{10000}] + [\frac{1000}{10000}]](https://tex.z-dn.net/?f=Probability%20%3D%20%5B%5Cfrac%7B1000%7D%7B10000%7D%5D%20%2B%20%5B%5Cfrac%7B1000%7D%7B10000%7D%5D)
![Probability = [\frac{1}{10}] + [\frac{1}{10}]](https://tex.z-dn.net/?f=Probability%20%3D%20%5B%5Cfrac%7B1%7D%7B10%7D%5D%20%2B%20%5B%5Cfrac%7B1%7D%7B10%7D%5D)



or

Answer:
4 feet/minute
explanation:
The rate of descent = (10 feet)/(2.5 mn) = 4 ft/min
Answer:50
Step-by-step explanation:
All you do is add 60 and 70 together and then subtract what you had got from 180 witch gives you the answer for y and sense x is vertical to y they are going to be the same.
I believe the equation is
![4 \sqrt[4]{2x} + 6 \sqrt[4]{2x}](https://tex.z-dn.net/?f=4%20%5Csqrt%5B4%5D%7B2x%7D%20%2B%206%20%20%5Csqrt%5B4%5D%7B2x%7D%20)
In this case, you would simplify it by adding them together.
![4 \sqrt[4]{2x} + 6 \sqrt[4]{2x}](https://tex.z-dn.net/?f=4%20%5Csqrt%5B4%5D%7B2x%7D%20%2B%206%20%20%5Csqrt%5B4%5D%7B2x%7D%20)
=
![10 \sqrt[4]{2x}](https://tex.z-dn.net/?f=10%20%20%5Csqrt%5B4%5D%7B2x%7D%20)
And can even be changed to an exponential equation:
If you don’t your answer will not be correct also when you use them it helps you find the correct answer