Answer:
Simple random sampling
Step-by-step explanation:
Every element of the population does have an equal probability of getting chosen in a basic random sampling. The entire population should be included in your sample frame. To conduct this sort of sampling, technologies such as random numbers or other approaches relying completely on chance can be used.
t = 
multiply both sides by 6rt
6crt = 1 ( divide both sides by 6ct to obtain r )
t = 
Answer:
We can not solve for a unique cost for each soldier.
Step-by-step explanation:
Let x be the daily cost for legionaries and y be the daily cost for archers.
Upon using our given information we will get a system of linear equations as:


Now we will solve for x from our 2nd equation,

Now we will substitute this value in our 1st equation.

We can see that -3y cancels out with 3y and 9 is not equal to 10. So this is an unsolvable system. Therefore, we can not find a unique cost for each soldier.
Answer:
11/12
Explanation:
1/3 + 3/2 = 11/6
11/6 x 1/2 (average is halfway) = 11/12
if you meant x^2+9x+20 then it is (x+4)(x+5) you know that because 4+5=9 and 4x5=20 using FOIL