Answer:
Katherine invested $12,000
Step-by-step explanation:
Use formula

where
I = interest,
P = principal,
r = rate (as decimal),
t = time (in years).
In your case,
t = 1 year,
r = 0.06 (or 6%)
P + I =$12,720, thus

Answer:
3 < c < 9
Step-by-step explanation:
The length of a side of a triangle cannot be negative. This eliminates the first and last options.
The addition of two sides of a triangle must be greater than the third side. In this case:
3 + 6 = 9 > c
So, the second option is correct. The third option is not correct, because, for example, c = 8 is possible
We can write an equation of this, with p representing the unknown population. We know that 90% of the population owns cars:
90% * p
We also know that 4761 people own cars, which is the same as the above expression, so we write:
90% * p = 4761.
From there, you just divide both sides by 90%, or 0.9
p = 4761/0.9 = 5290
The population is 5290 people.