The fraction 8/21 cannot be simplified because the numerator and denominator don't have a common factor except 1.
Answer:
a) P(X∩Y) = 0.2
b)
= 0.16
c) P = 0.47
Step-by-step explanation:
Let's call X the event that the motorist must stop at the first signal and Y the event that the motorist must stop at the second signal.
So, P(X) = 0.36, P(Y) = 0.51 and P(X∪Y) = 0.67
Then, the probability P(X∩Y) that the motorist must stop at both signal can be calculated as:
P(X∩Y) = P(X) + P(Y) - P(X∪Y)
P(X∩Y) = 0.36 + 0.51 - 0.67
P(X∩Y) = 0.2
On the other hand, the probability
that he must stop at the first signal but not at the second one can be calculated as:
= P(X) - P(X∩Y)
= 0.36 - 0.2 = 0.16
At the same way, the probability
that he must stop at the second signal but not at the first one can be calculated as:
= P(Y) - P(X∩Y)
= 0.51 - 0.2 = 0.31
So, the probability that he must stop at exactly one signal is:

Answer: 13,333 snowflakes
Step-by-step explanation:
For this exercise let be "x" represents the number of snowflakes that will be in the fort.
According to the information given in the exercise, the weight of one block is 1 kilogram. Knowing that the fort must have 40 blocks, the total weight is:

Since each snowflake weighs
grams, need to divide the total weight calculated above by the weight of a snowfake.
Therefore, through this procedure you get the following result:

Therefore, the there will be 13,333 snowflakes in the fort.
Answer:
C. 
General Formulas and Concepts:
<u>Calculus</u>
- Mean Value Theorem (MVT) - If f is continuous on interval [a, b], then there is a c∈[a, b] such that

- MVT is also Average Value
Step-by-step explanation:
<u>Step 1: Define</u>

f'(c) = 20
Interval [1, b]
<u>Step 2: Check/Identify</u>
Function [1, b] is continuous.
Derivative [1, b] is continuous.
∴ There exists a c∈[1, b] such that 
<u>Step 3: Mean Value Theorem</u>
- Substitute:

- Rewrite:

And we have our final answer!
1. 2/7
2. 2/15
3. 5/24
4. 2/11