ANSWER
0.756
EXPLANATION
Let x represent number of correct answers.
We can find
which leads us to
which uses the compliment of 
to find the probability of getting at least 2 questions correct.
Note that since 
and 
are mutually exclusive, we have
Then 
as we have 
to answer the questions incorrectly divided by the total 
to answer the questions.
Exactly 1 answer correct: 
Therefore
![\begin{aligned} P(x \ge 2) &= 1 - P(x = 0\text{ or }x =1) \\ &=1 - \big[P(x=0) + P(x=1)\big] \\ &=1 - \left[ (3/4)^{10} + {}_{10}C_1 \cdot (3/4)^9(1/4)^1 \right] \\ &\approx 0.756 \end{aligned}](https://tex.z-dn.net/?f=%5Cbegin%7Baligned%7D%0AP%28x%20%5Cge%202%29%20%26%3D%201%20-%20P%28x%20%3D%200%5Ctext%7B%20or%20%7Dx%20%3D1%29%20%5C%5C%0A%26%3D1%20-%20%5Cbig%5BP%28x%3D0%29%20%2B%20P%28x%3D1%29%5Cbig%5D%20%5C%5C%0A%26%3D1%20-%20%5Cleft%5B%20%283%2F4%29%5E%7B10%7D%20%2B%20%7B%7D_%7B10%7DC_1%20%5Ccdot%20%283%2F4%29%5E9%281%2F4%29%5E1%20%5Cright%5D%20%5C%5C%0A%26%5Capprox%200.756%0A%5Cend%7Baligned%7D%20)
Answer:
9
count all the whole squares
Answer:
d = C - 2/3
Step-by-step explanation:
Subtract 2/3 from both sides of the equation:
C = d + 2/3
-2/3 -2/3
-----------------
C - 2/3 = d
Answer:
1st term = 14
2nd term = 29
3rd term = 44
Step-by-step explanation:
1st term = 3 x (5 x 1) - 1
= 3 x 5 - 1
= 15 - 1 = 14
2nd term = 3 x (5 x 2) - 1
= 3 x 10 - 1
=30 - 1 = 29
3rd term = 3 x (5 x 3) -1
= 3 x 15 - 1
= 45 - 1 = 44
Answer:
y = -15
x = -10
Step-by-step explanation:
1/4x - 1/2 = 5 (1)
3x + 2/3y = -40 (2)
Multiply (1) by 4
1/4x - 1/2 = 5
1/4x * 4 - 1/2y * 4 = 5 * 4
4/4x - 4/2y = 20
x - 2y = 20 (3)
Multiply (2) by 3
3x + 2/3y = -40 (2)
3x * 3 + 2/3y * 3 = -40 * 3
9x + 6/3y = -120
9x + 2y = -120 (4)
x - 2y = 20 (3)
9x + 2y = -120 (4)
Using elimination method, Add (3) and (4)
9x + x = -120 + 20
10x = -100
x = -100/10
x = -10
Substitute x = -10 into (3)
x - 2y = 20 (3)
-10 - 2y = 20
-2y = 20 + 10
-2y = 30
y = 30/-2
y = -15
y = -15
x = -10
