A balanced coin will have 50:50 chance of showing either head or tail. In this question, you are asked the probability to find the first head after two tosses. That means the toss result should be:
1. tail = 1/2 probability
2. head = 1/2 probability
Previously you are tossing the coin 10 times and obtain zero head. But this previous 10 tosses result should not influence your probability in the 11th and 12th toss. The chance will always be 50:50 no matter how much the tosses count. So the probability should be: 1/2 * 1/2= 1/4
Answer:
The answer is 
Step-by-step explanation:
Answer:
B
Step-by-step explanation:
The roof will be in the shape of an isosceles triangle with a base length of 30 m and two sides that are 17 m. The two 17 m beams will have the same angle of elevation since they have to might in the middle.
So to find the angle of elevation, we can split the roof in half vertically to create a right triangle. The base will now be 15 m, and the hypotenuse will be 17. Now we can use a trigonometry function to solve for the angle. We know the hypotenuse and the side adjacent to the angle, so we can use cosine.




The answer is 28.1 degrees
Answer:
66.42°
Step-by-step explanation:
Given
cos ? =
, then
? =
(
) ≈ 66.42° ( to the nearest hundredth )