Answer:
Step-by-step explanation: explique melhor
<h3>
Answer: A) 5.4%</h3>
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Explanation:
We use the binomial probability formula here
P(k) = (n C k)*(p)^k*(1-p)^(n-k)
In this case, there are n = 12 trials and p = 0.5 is the probability of getting heads. The value of k = 3 means we want 3 heads.
So,
P(k) = (n C k)*(p)^k*(1-p)^(n-k)
P(3) = (12 C 3)*(0.5)^3*(1-0.5)^(12-3)
P(3) = 220*(0.5)^3*(1-0.5)^(12-3)
P(3) = 0.0537109375
P(3) = 0.054
P(3) = 5.4%
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Side note: the n C k refers to the nCr combination formula

where the exclamation marks mean factorials. You could also use Pascal's Triangle as an alternative for this portion.
Step-by-step explanation:
Angles APD, DPC and CPB are supplementary. (Angles on a straight line)
Therefore Angle APD + Angle DPC + Angle CPB = 180°.
Since Angle DPC = 90° (Right angle),
Angle APD + Angle CPB = 180° - 90° = 90°.
=> (7x + 1) + (9x - 7) = 90
=> 16x - 6 = 90
=> x = 6
Hence arc measure of minor arc AD
= (7x + 1)° = [7(6) + 1]° = 43°.