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Total possible valid combinations:

Case 1: Hugo is the pilot:

1 * 3C2 = 3
(We select Hugo as the pilot and then we can select 2 co pilots only out of the 3 qualified ones)

Case 2: Hugo is not the pilot:

3C1 * 6C2 = 45

Total = 48

Now, probability of selecting 1 combination where H is the pilot out of 48: 3/48 = 1/16

Probability of selecting exactly 1 co pilot with less than 5 hours:

1. This means, we can not select any combination that includes Hugo and
2. 1 copilot is selected from the 3 that have 500+ hours and one is selected from the 3 that have less than 500 hours of experience

= 3C1 * 3C1 * 3C1 = 27

Probability = 27/48 = 9/16
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We are told that Hugo is selected only if each of the other co-pilots have 500 hours of flight experience
This means that if hugo is selected then the other two pilots have to belong to the 500 hour group

So total sample size
= Select Hugo = 1 way, Select 2 from the other 3 i.e 3C2 = 3 ways
= other than hugo = 3 ways x 6C2 = 3 x 15 = 45 ways

Hence total sample size = 48

So prob of selecting hugo = 1 x 3C2/48 = 1/16

Prob of selecting exactly one pilot from the 500 hour group

This is the case excluding hugo hence 3 x 3C1 x 3C1 / 48 = 27 /48 i.e 9/16


Bunuel
The cockpit crew for a long-haul flight must consist of 1 pilot and 2 copilots, selected from an available pool of 4 pilots and 6 copilots. One of the pilots, Hugo, is only certified to serve as pilot if each of the two selected copilots has at least 500 hours of flight experience, a qualification held by 3 of the 6 available copilots. The remaining pilots can fly with any copilot. A cockpit crew will be selected at random from all possible crew combinations that meet these conditions.

The two columns in the table refer to two separate cases, each based on the same random selection from all valid cockpit crews. In the table, for Hugo is the pilot, select the probability that Hugo is the pilot on the selected cockpit crew. For Exactly 1 copilot has less than 500 hours, select the probability that exactly 1 of the 2 copilots on the selected cockpit crew has less than 500 hours. Make only two selections, one in each column.
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We have Pilots (P) and Co-pilots (C).
A valid crew consists of: 1 P and 2 C

P = 4 and C = 6

One of the pilots, Hugo, has a constraint on who can fly as co-pilot with him. Each of the co-pilots accompanying Hugo in the cockpit must have a minimum of 500 hours of flight experience i.e., >=500 hours. 3 out of 6 co-pilots meet this criteria.
Hence, if Hugo is to be the pilot in the crew, there are 3C2 combinations (or 3!/2!) of valid co-pilots.
Therefore, if Hugo is to be the pilot, there are 3 ways in which the qualifying co-pilots can be arranged to make a valid crew.

Also, we have 3 pilots remaining, other than Hugo, who can be accompanied by any 2 co-pilots without any constraints. Therefore, the total number of possible combinations for these 3 pilots = 3 x (6C2) = 3 x 15 = 45 possible ways.

Therefore, the total number of valid combinations of 1 pilot and 2 co-pilots is 45 + 3 = 48.

1. Now, for the first part of the question, we need to calculate the probability that Hugo is the pilot. This amounts to 3 out of 48 possible ways which can be written as 3/48 = 1/16.

2. Next, for the second part of the question, we need to calculate the number of ways in which the pilots and co-pilots can be arranged where exactly 1 of the co-pilots has less than 500 hours of flying experience. Since only 2 co-pilots can be in a valid crew, this means the other co-pilot has >=500 hours of flying experience. Hence, for each valid crew for this constraint, we have 3 co-pilots for each position (i.e., 3 co-pilots with <500 hours and 3 co-pilots with >=500 hours).
Therefore, the total number of combinations for the co-pilots is 3 x 3 = 9.
Now, for it to be a valid crew, they also need 1 pilot. But Hugo doesn't qualify for this condition since he can only be part of the crew if BOTH the co-pilots have minimum 500 hours. Hence, the 9 combinations of co-pilots can be put against 3 pilots. Therefore, total number of valid combinations for the constraint in this question= 9 x 3 = 27. And we know that the total number of valid crews is 48. Therefore, the probability that exactly 1 of the copilots has less than 500 hours is 27/48 = 9/16.

Final answers: 1/16 and 9/16.
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Total Combinations Possible:
Hugo + Rest of the pilots
T = 1 * (3C2) + 3 * (6C2) = 16*3 = 48

Part 1. Hugo... : H = 1 * (3C2) = 3
Prob(Hugo is pilot) = 3/48 = 1/16

Part 2. Exactly One copilot has < 500 Exp: X = 3C1 * 3C1 * 3C1 = 27
Prob(Exactly One Coplit...) = 27/48 = 9/16
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We have 1 rule:
If hugo is selected for pilot then, both copilots should be from 3 people out of 6.
when hugo is selected then no of ways the team can be formed is, 1 way hugo and 3c2 ways co-pilots. so 3 ways.

And when exactly 1 copilot is selected with >500 flights then hugo wont be selected as pilot. so 3 ways to select pilot
and 3c1 x 3c1 for co-pilots => 3 x 3 x 3 =>27

Now our sample space would be, if hugo get selected then 3 ways, or if doesnt, 3 ways(1 pilot) and 6c2(co-pilots)
=> 3+ 3*15 => 48

Now answer for first is when hugo selected => 3/48 = 1/16 for the first option.
When exactly 1 co-pilot is >500 selected => 27/48 = 9/16 for the second option.
Bunuel
The cockpit crew for a long-haul flight must consist of 1 pilot and 2 copilots, selected from an available pool of 4 pilots and 6 copilots. One of the pilots, Hugo, is only certified to serve as pilot if each of the two selected copilots has at least 500 hours of flight experience, a qualification held by 3 of the 6 available copilots. The remaining pilots can fly with any copilot. A cockpit crew will be selected at random from all possible crew combinations that meet these conditions.

The two columns in the table refer to two separate cases, each based on the same random selection from all valid cockpit crews. In the table, for Hugo is the pilot, select the probability that Hugo is the pilot on the selected cockpit crew. For Exactly 1 copilot has less than 500 hours, select the probability that exactly 1 of the 2 copilots on the selected cockpit crew has less than 500 hours. Make only two selections, one in each column.
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The question says that the crew will be selected from all crew combinations. Hence we need to first find the total number of crew combos possible. These can be broadly divided in 2 parts
1. Where Hugo is the pilot
2. Where other 3 are the pilot

Let's assume the 6 copilots are E1, E2, E3, NE1, NE2, NE3 where E1, E2, E3 are the >500 hours experienced copilots and the other 3 are non experienced. Similarly the 4 pilots are Hugo, P1, P2, P3.

1. Crew possibilities where Hugo is the pilot.
H+E1+E2
H+E2+E3
H+E1+E3

2. Crew possibilities where any of the other 3 are pilots.
Since the other 3 pilots don't have any restriction on the type of copilots, we can pick any 2 out of 6 which is 6C2 = 15
With these 15 pairs of copilots, we can either have P1 or P2 or P3 as pilot. so 15*3 = 45 possibilities

Total crews possible = 3+45=48

A. Now, probability where Hugo is pilot = Favorable/Total = 3/48 = 1/16

B. Probability where 1 copilot has <500 hours experience

Pick 1 copilot out of 3 experienced ones = 3C1
Pick 1 out of the 3 inexperienced ones = 3C1
Pick one of the 3 pilots = 3C1

Favorable cases = 3*3*3
Total = 48
Probability = 27/48 = 9/16
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Hugo is pilot:

favorable: hugo as pilot = 1C1*3C2 = 3 ways
total possible: hugo as pilot + hugo not as pilot = 3 + (3C1*6C2) = 3 + 45 = 48 ways

probablity = 3/48 = 1/16

exactly one copilot is less than 500 hrs:

favorable: exactly one copilot less than 500 hrs = 3C1*3C1*3C1 = 27 ways
total possible: exactly one copilot <500hrs + none copilot<500hrs + both copilots<500hrs = 27 + 3C2*4C1 + 3C2*3C1 = 27 + 12 + 9 = 48 ways
probability = 27/48 = 9/16
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Total outcome = When Hugo is selected pilot + when Hugo is not selected Pilot
When Hugo is selected= 1*3C2 = 3 (Hugo and 2 copilots from 3 who have at least 500 hrs)
When Hugo is not selected= 3C1*6C2 = 45(Select one pilot from other 3 pilots and any 2 copilots pilots from a pool of 6)
Total outcome= 3+45= 48

1)Prob when Hugo is selected= 3/48= 1/16
2)Prob when exactly one copilot with atleast 500 hrs is selected= Fav outcome/Total outcome= 27/48 = 9/16
Fav outcome= 3C1*3C1*3C1 = 27 (1 out of 3 pilots (other than Hugo) * 1 out of 3 copilots who have atleast 500 hrs * 1 out of rest of copilots)

Bunuel
The cockpit crew for a long-haul flight must consist of 1 pilot and 2 copilots, selected from an available pool of 4 pilots and 6 copilots. One of the pilots, Hugo, is only certified to serve as pilot if each of the two selected copilots has at least 500 hours of flight experience, a qualification held by 3 of the 6 available copilots. The remaining pilots can fly with any copilot. A cockpit crew will be selected at random from all possible crew combinations that meet these conditions.

The two columns in the table refer to two separate cases, each based on the same random selection from all valid cockpit crews. In the table, for Hugo is the pilot, select the probability that Hugo is the pilot on the selected cockpit crew. For Exactly 1 copilot has less than 500 hours, select the probability that exactly 1 of the 2 copilots on the selected cockpit crew has less than 500 hours. Make only two selections, one in each column.
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4 pilots total, including Hugo
6 copilots:3 experienced>500hrs
3 less<500hrs
Probability of Hugo being a pilot
if Hugo is pilot both copilots must be experienced
with hugo(3/2)=3 choices
sice Hugo is not the pilot, any 2 of the 6can be chosen
3.(6/2)=45crews
total valid=3+45=48 crew
making P(Hugo)=3/48=1/16
pob that exactly 1 copilot has less than 500hrs
(3/1) (3/1) =9 pairs
since hugo is out, only the other 3 pilots can be used:3*9=27 crews
P (exactly 1 low-hour copilot) =27/48=9/16

Hugo is the pilot:1/16
Exactly 1 copilot has less than 500hours: 9/16
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Let the 3 copilots with 500+ hrs be experienced and the other 3 be less experienced

Valid cockpit crews:
-> Hugo can only fly with 2 experienced copilots : 3C2 = 3 crews
-> Each of the other 3 pilots can fly with any 2 copilots: 6C2 = 15 crews each
Total valid crews = 3 + 3*15 = 48

Hugo is the pilot : 3/48 = 1/16

Exactly 1 copilot has less than 500 hrs:
Choose 1 experienced & 1 less experienced copilot: 3C1 * 3C1 = 9 pairs
Hugo can't fly with these pairs, so only the other 3 pilots are possible.
Favorable crews = 3*9 = 27
Probability = 27/48 = 9/16

Ans:
Hugo is the pilot : 1/16
Exactly 1 copilot has less than 500 hrs : 9/16
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so hugo needs 2 pilots with experience,
so from 3 eligible ones you are choosing 2, so = 3

for the other 3 pilots, any of the 6 must be selected, so
3x 6x5/3x2 = 45

total 45+3 = 48

Hugo is the pilot = 3/48 = 1/16

exactly oe copilot has less than 500 hours

3 experienced and 3 less experienced = 9

there are 3 possible pilots as higo cannot pilot with any of these so 9x3 = 27

so 27/48 = 9/16
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Total number of ways crews can be made can be arrived at using factorials. Use the formula 3!/2!*1! for when hugo is the pilot which will come down to 3 and then other pilots 6!/4!*2! which is 15 and multiply by 3 for all 3 pilots, hence 48 is total ways. Now notice, Hugo is pilot only 3 times hence 3/48 will be 1/16 and P that 1 copilot has less than 500hrs will be 3*3*3 which is 27/48 and that is 9/16 which is our answer.
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Hugo can only be paired with 2 qualified copilots (Q). The other 3 pilots can be paired with any 2 of the 6 copilots.

Total valid crew:

Hugo - C(3,2) = 3
Other pilots = 3* C(6,2) = 3*15 = 45

Total Crews = 48

P (Hugo is the pilot) = 3/48 = 1/16

To have exactly 1 copilot with fewer than 500 hours, the crew must have 1 qualified (Q) and 1 unqualified copilot (U).

Hugo: Not possible, as only qualified copilots are required
Other pilots: 3 Q * 3U = 9

Total Favourable crews = 3*9 = 27

P (exactly one unqualified copilot) = 27/48 = 9/16
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FIRST PART: Probability that Hugo id the pilot
I need to consider 2 scenarios:
- A: Hugo is the pilot.
- B: Hugo is not the pilot.

Scenario A: Hugo is the pilot
Hugo can be selected as the pilot in only one way.
Since the crew must include 2 copilots with at least 500 hours of experience, we select 2 of the 3 qualified copilots:
\((\frac{3}{2})=\) \(\frac{3x2}{2x1} = 3 \)
Therefore, the number of crew in which Hugo is the pilot is:
\(1x3=3\)

Scenario B: Hugo is not the pilot
There are other pilots.
When Hugo is not the pilot , any 2 of the 6 copilots can be selected:
\(\frac{6}{2}\)\( = \frac{6x5}{2x1}=15\)
The number of crew in which Hugo is not the pilot is: \(3X15=45\)

Total number of valid crews \(3+45=48\)

Probability that Hugo is the pilot is: \(\frac{3}{48}=\frac{1}{16}\)

SECOND PART: Probability that exactly one pilot has fewer than 500 hours
Hugo cannot be the pilot in this case.
Therefore, there are 3 possible pilots.
To have exactly one pilot with fewer than 500 hours, we must select:

- 1 of the 3 inexperienced copilots: \(\frac{3}{1}=3\)
- 1 of the experienced copilots:\(\frac{ 3}{1}=3\)
Number of favorable crews is: \(3x3x3 =27\)
\(\frac{27 ways}{ 48 total ways} \) \(= \frac{9}{16}\)

Final answers:
1.- \(\frac{1}{16}\)
2.- \(\frac{9}{16}\)

Bunuel
The cockpit crew for a long-haul flight must consist of 1 pilot and 2 copilots, selected from an available pool of 4 pilots and 6 copilots. One of the pilots, Hugo, is only certified to serve as pilot if each of the two selected copilots has at least 500 hours of flight experience, a qualification held by 3 of the 6 available copilots. The remaining pilots can fly with any copilot. A cockpit crew will be selected at random from all possible crew combinations that meet these conditions.

The two columns in the table refer to two separate cases, each based on the same random selection from all valid cockpit crews. In the table, for Hugo is the pilot, select the probability that Hugo is the pilot on the selected cockpit crew. For Exactly 1 copilot has less than 500 hours, select the probability that exactly 1 of the 2 copilots on the selected cockpit crew has less than 500 hours. Make only two selections, one in each column.
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total valid crew combinations= Hugo is selected + Hugo is not selected= 3C2 + 3C1*4C2= 48

when Hugo is selected probability= 3/48=1/16
Exactly 1 copilot has <500 hrs= 3C1*3C1*3C1= 9/16

Bunuel
The cockpit crew for a long-haul flight must consist of 1 pilot and 2 copilots, selected from an available pool of 4 pilots and 6 copilots. One of the pilots, Hugo, is only certified to serve as pilot if each of the two selected copilots has at least 500 hours of flight experience, a qualification held by 3 of the 6 available copilots. The remaining pilots can fly with any copilot. A cockpit crew will be selected at random from all possible crew combinations that meet these conditions.

The two columns in the table refer to two separate cases, each based on the same random selection from all valid cockpit crews. In the table, for Hugo is the pilot, select the probability that Hugo is the pilot on the selected cockpit crew. For Exactly 1 copilot has less than 500 hours, select the probability that exactly 1 of the 2 copilots on the selected cockpit crew has less than 500 hours. Make only two selections, one in each column.
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Random selection from all valid cockpit crews, meaning we cannot choose Hugo from 4 pilots alone.
Total copilot pairs = 6c2 = 15
If both copilots are qualified, 3c2 = 3
Therefore, Hugo appears in 3 valid crews
For other 3 pilots, we have 15 x 3 = 45 valid crews
Total valid crews = 45 + 3 = 48
Hugo is the pilot = 3/48 = 1/16 (Answer)
Exactly 1 copilot has less than 500 hours experience, meaning 1 from experienced = 3c1 x 3c1 = 3x3 = 9
Since Hugo cannot fly with those 9 pairs, we have to select other 3 pilots.
Total will be 3x9 = 27
Therefore, exactly 1 copilot = 27/48 = 9/16 (Answer)
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Two probabilities we need to find, P(Hugo is the pilot) and P(Exact 1 <500 hrs).

Let's start with the pilot.
There are 2 ways we can forms the cockpit team,
1. Hugo is the pilot
- P(Hugo) = 1
- P(Crews) = 3 choose 2 = 3
- Total prob of this case is 1*3 = 3
2. Hugo isn't
- P(Hugo isn't) = 3 choose 1 = 3
- P(Crews) = 6 choose 2 = 6!/4!2! = 15
- Total prob of this case is 45

So, we can answer P(Hugo) = 3/48 = 1/16.

Next, focus on the probability of forming the cockpit team with exactly 1 copilot who has <500 hrs.
There are 3 ways to form,
1. Two <500 hrs
- This case: 3 choose 2 = 3
2. Two ≥500 hrs
- 3 choose 2 = 3 as well
3 One <500, one ≥500 hrs
- 3 choose 1 * 3 choose 1 = 3*3 = 9

So, the probability that the copilot has <500 hrs is 9/15 = 3/5.

But we're finding the probability of forming the valid cockpit team; we must account for the pilot as well, where the exact case of 1 has <500 hrs can happen ONLY when Hugo isn't the pilot.

Therefore, we conditioned on P(Hugo isn't the pilot) = 15/16 * 3/5 = 9/16.
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