<u>Answer:</u>
<u>Distance:</u> 6x + 15.5y > 55.5
<u>Time:</u> x + y > 4.5
<u>Step-by-step explanation:</u>
We are given that Martha is training for a duathlon and she covered a total distance of over 55.5 miles in more than than 4.5 hours of training.
Also, she runs at a speed of 6 mph and bikes at a rate of 15.5 mph.
We are to write inequalities representing the distance she traveled and the total time she spent training.
<u>Distance:</u> 6x + 15.5y > 55.5
(formula for distance = speed x time so speeds for running and biking are multiplied by their number of hours)
<u>Time:</u> x + y > 4.5
(she trained for more than 4.5 hours, x hours for running and y hours for biking.
Answer:
x
=
1
+
i
√
2
,
1
−
i
√
2
Step-by-step explanation:
Answer:
The probability is 0.0052
Step-by-step explanation:
Let's call A the event that the four cards are aces, B the event that at least three are aces. So, the probability P(A/B) that all four are aces given that at least three are aces is calculated as:
P(A/B) = P(A∩B)/P(B)
The probability P(B) that at least three are aces is the sum of the following probabilities:
- The four card are aces: This is one hand from the 270,725 differents sets of four cards, so the probability is 1/270,725
- There are exactly 3 aces: we need to calculated how many hands have exactly 3 aces, so we are going to calculate de number of combinations or ways in which we can select k elements from a group of n elements. This can be calculated as:

So, the number of ways to select exactly 3 aces is:

Because we are going to select 3 aces from the 4 in the poker deck and we are going to select 1 card from the 48 that aren't aces. So the probability in this case is 192/270,725
Then, the probability P(B) that at least three are aces is:

On the other hand the probability P(A∩B) that the four cards are aces and at least three are aces is equal to the probability that the four card are aces, so:
P(A∩B) = 1/270,725
Finally, the probability P(A/B) that all four are aces given that at least three are aces is:
