Answer:
The probability is 0.9211
Step-by-step explanation:
Let's call K the event that the student know the answer, G the event that the student guess the answer and C the event that the answer is correct.
So, the probability P(K/C) that a student knows the answer to a question, given that she answered it correctly is:
P(K/C)=P(K∩C)/P(C)
Where P(C) = P(K∩C) + P(G∩C)
Then, the probability P(K∩C) that the student know the answer and it is correct is:
P(K∩C) = 0.7
On the other hand, the probability P(G∩C) that the student guess the answer and it is correct is:
P(G∩C) = 0.3*0.2 = 0.06
Because, 0.3 is the probability that the student guess the answer and 0.2 is the probability that the answer is correct given that the student guess the answer.
Therefore, The probability P(C) that the answer is correct is:
P(C) = 0.7 + 0.06 = 0.76
Finally, P(K/C) is:
P(K/C) = 0.7/0.76 = 0.9211
Step-by-step explanation:
<u>Using Pythagorus theorem</u> :
(A)
(B)
Answer: The answer is 50
Step-by-step explanation:
I did the test
Hello :
to complete the factorization <span>unit tiles are needed :
</span>"3 negative unit tiles" and "<span>4 positive unit tiles"because : -3 and 4 are roots for
x²-x-12
x²-x-12 = (x+3)(x-4)</span>
To solve this question, we can do it both ways. we can get rid of the 7 by dividing it, or we can distribute it to the parenthesis. let's do this the distribution way.
63=7(5+7b)
When distributing, the number behind (7) goes to both and all terms in the parenthesis.
63=7(5)+7(7b)
Multiply.
63=35+49b
Subtract 35.
28=47b
Divide by 49.
0.57=b
