2+3x(8+4)=38
2+3x12=38
2+36=38
38=38
For each question, there is a 1/2 chance at getting the question correct by guessing.
Let's take a scenario to better understand.
Suppose the true-false paper has 5 questions. For a perfect score by guessing, you'd need to get all 5 correct (ie (1/2)⁵)
The reason why you multiply is because you need each 1/2 simultaneously for a perfect score, which is an important concept when doing binomial probability later on.
Thus, let's use this knowledge to answer the question.
We need the minimum amount of questions such that the probability is less than 1/10.
We can write an inequality for this:

Now, we need to log both sides to find n.

n > 3.3219...
n ≈ 4
Thus, 4 questions is the minimum number of questions needed.
Answer:
Is possible
Step-by-step explanation:
It is possible to add and subtract fractions
Answer:
Step-by-step explanation:
Comment
If 4 numbers have an average of 9, then total of the 4 numbers is 4 * 9 = 36.
If one of the 4 numbers is a 7, then
7 + x = 36 where x is the sum of the other 3 numbers.
7 + x = 36 Subtract 7 from both sides
7- 7 +x = 36 - 7
x = 29
Answer 29
Angle = 36 degrees =

=

now, radius = 10 cm
so arc = radius x angle = 10 x pi/5 = 2pi = 6.28 cm