Because supplementary angles means mA + mB = 180.
Then subtract 80 from 180 which will get you 100.
So B = 100
Answer:
(a)

(b)
i.


ii.


iii.


Step-by-step explanation:
Given



Solving (a): List all possible elements using set-roster notation.
The possible elements are:

And the number of elements are:

Solving (bi) Exactly 1 girl
From the list of possible elements, we have:

And the number of the list is;

The probability is calculated as;



Solving (bi) At least 2 are girls
From the list of possible elements, we have:

And the number of the list is;

The probability is calculated as;



Solving (biii) No girl
From the list of possible elements, we have:

And the number of the list is;

The probability is calculated as;



Answer as an improper fraction = 16/5
Answer as a mixed number = 3 & 1/5
Answer in decimal form = 3.2
All of those values represent the same thing, but written in a different way.
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Explanation:
I'm assuming HM stands for Harmonic Mean in this case.
If so, then we apply the reciprocal operation to each value to get 1/2 and 1/8 (from 2 and 8 respectively).
Add up those fractions:
1/2 + 1/8 = 4/8 + 1/8 = 5/8
Now we'll divide n = 2 over that result. The n = 2 refers to the number of items in the original set.
n divide over (5/8) = 2*(8/5) = 16/5 which is the answer as an improper fraction
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To convert to a mixed number, we can do the following:
16/5 = (15+1)/5
16/5 = 15/5 + 1/5
16/5 = 3 + 1/5
16/5 = 3 & 1/5
Or if you need the answer in decimal form, then using a calculator would get you 16/5 = 3.2
Answer:
115.08
Step-by-step explanation:
For this problem, I'd use cross-multiplication.
9/12 = x/8.
When cross multiplying, multiply 12*x and 9*8. This leads to a new equation:
12x = 72.
Then you solve as an algebra problem.
*Divide 12 on both sides*
x = 6.