Answer:
The correct answer is B) 18%
Step-by-step explanation:
Note that the vaccine is already and is 80% effective. This means that if the entire population was administered with the vaccine, only 8/10 would gain immunity leaving 2/10 or 0.2 exposed.
If the new vaccine, therefore, is supposed to be 90% effective, it is only pragmatic to administer it against those who do not have immunity which is 0.2 of the existing population.
So to get the percentage that will develop immunity, we have:
0.2 x 0.9 = 0.18 or 18%
Cheers!
Answer:
x = -2, y = -2
Step-by-step explanation:
Your goal is to try and cancel out a variable. I want to get rid of y so i subtracted the first equation from the second one.
After that I solve for x and got x=-2.
I used x=-2 and plugged it back into either of the equation to solve for y.
Distribution of properties
Answer:
340 phones
Step-by-step explanation:
Make an expression
She repairs 10 phones each day, d.
Each day she repairs 10 phones, it is 10 phones off the total number (450) she has to repair, so we can subtract 10d from 450.
450-10d
We want to find how many she has left after 11 days, so we can substitute 11 in for d
450-10(11)
Multiply
450-110
340
She will still have 340 phones left to repair
