Answer:
Option A is correct.
Step-by-step explanation:
We are given:
We need to find the value of a.
The LCM of (2+i) and (3+i) is (2+i)(3+i)
Now rationalize the denominator by multiplying by 5-5i/5-5i
We are given
Now after solving we have:
So value of a = 1/10 and value of b = -1/10
So, Option A is correct.
Answer: - 0.28
Explanation:
1) Expected value: is the weighted average of the values, being the probabilities the weight.
That is: ∑ of prbability of event i × value of event i.
In this case: (probability of getting 2 or 12) × (+6) + (probability of gettin 3 or 11) × (+2) + (probability of any other sum) × (-1).
2) Sample space:
Sum Points awarded
1+ 1 = 2 +6
1 + 2 = 3 +2
1 + 3 = 4 -1
1 + 4 = 5 -1
1 + 5 = 6 -1
1 + 6 = 7 -1
2 + 1 = 3 +2
2 + 2 = 4 -1
2 + 3 = 5 -1
2 + 4 = 6 -1
2 + 5 = 7 -1
2 + 6 = 8 -1
3 + 1 = 4 -1
3 + 2 = 5 -1
3 + 3 = 6 -1
3 + 4 = 7 -1
3 + 5 = 8 -1
3 + 6 = 9 -1
4 + 1 = 5 -1
4 + 2 = 6 -1
4 + 3 = 7 -1
4 + 4 = 8 -1
4 + 5 = 9 -1
4 + 6 = 10 -1
5 + 1 = 6 -1
5 + 2 = 7 -1
5 + 3 = 8 -1
5 + 4 = 9 -1
5 + 5 = 10 -1
5 + 6 = 11 +2
6 + 1 = 7 -1
6 + 2 = 8 -1
6 + 3 = 9 -1
6 + 4 = 10 -1
6 + 5 = 11 +2
6 + 6 = 12 +6
2) Probabilities
From that, there is:
- 2/36 probabilities to earn + 6 points.
- 4/36 probabilites to earn + 2 points
- the rest, 30/36 probabilities to earn - 1 points
3) Expected value = (2/36)(+6) + (4/36) (+2) + (30/36) (-1) = - 0.28
Answer:
c 2:1
Step-by-step explanation:
If you simplify 14:7 it is 2:1 (divide by 7)
Only 20%of earths water is useable
Answer:
Please see attachment
Step-by-step explanation:
Please see attachment
