The product of the sum of the their rates and the time it took them to finish the job should be equal to one whole job. This may be expressed by the equation,
(1/9 + r) x 6 = 1
Solving for the value of r gives an answer of r = 1/18. Thus, Hector does 1/18 of the job in 1 hour.
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:
y=3x+7
Step-by-step explanation:
y=mx+c
m=3 parallel lines have the same gradient
(-2,1)
(x,y)
y=mx+C
1=3x-2+c
1=-6+c
c=7
y=3x+7
Answer:
180
Step-by-step explanation:
why does it have to be 20 character long