Probability Problems Multiple
1. **Problem 02: Probability with card selections**
(a) Find the probability the second card is a face card given the first card was red.
- A standard deck has 52 cards: 26 red, 26 black.
- Number of face cards: 12 (Jack, Queen, King of each suit). Half are red (6) and half are black (6).
- Since the first card is red and replaced, the deck composition remains unchanged for second draw.
- Probability(second card is face card | first card red) = Probability(second card is face card) = $\frac{12}{52} = \frac{3}{13} \approx 0.2308$.
(b) Find the probability second card is an ace given the first was a face card.
- 4 aces in the deck. Since replacement, deck unchanged.
- Probability(second card is ace | first card face card) = Probability(second card is ace) = $\frac{4}{52} = \frac{1}{13} \approx 0.0769$.
(c) Find the probability second card is a black jack given the first card was a red ace.
- There are 2 black jacks in a deck (Jack of spades and Jack of clubs).
- First card red ace replaced, deck unchanged.
- Probability(second card is black jack | first red ace) = Probability(second card is black jack) = $\frac{2}{52} = \frac{1}{26} \approx 0.0385$.
2. **Problem 03: Probability from prison escape data**
- Total seasons each: 45 (Winter, Spring, Summer, Fall).
(a) Probability escapes between 16 and 20 in winter:
- Escapes between 16 and 20 in winter = 3 seasons.
- Total winter seasons = 45.
- Probability = $\frac{3}{45} = \frac{1}{15} \approx 0.0667$.
(b) Probability more than 10 escapes attempted in summer:
- Categories >10: 11–15 (7), 16–20 (6), 21–25 (5), More than 25 (4).
- Sum = 7 + 6 + 5 + 4 = 22.
- Total summer seasons = 45.
- Probability = $\frac{22}{45} \approx 0.4889$.
(c) Probability escapes between 11 and 20 in any season (all seasons combined):
- Categories combined: 11–15 + 16–20.
- Sum for each season:
- Winter: 5 + 3 = 8
- Spring: 8 + 4 = 12
- Summer: 7 + 6 = 13
- Fall: 7 + 5 = 12
- Total combined = 8 + 12 + 13 + 12 = 45.
- Total seasons = 45 * 4 = 180.
- Probability = $\frac{45}{180} = \frac{1}{4} = 0.25$.
3. **Problem 04: Probability from socio-economic survey**
- Total respondents = 1000.
(a) Probability respondent is Undergraduate (U):
- Total U = 300.
- Probability = $\frac{300}{1000} = 0.3$.
(b) Probability respondent is Graduate (G):
- Total G = 700.
- Probability = $\frac{700}{1000} = 0.7$.
(c) Probability respondent is Female (F):
- Total F = 400.
- Probability = $\frac{400}{1000} = 0.4$.
(d) Probability Male-Graduate (MG):
- MG = 450.
- Probability = $\frac{450}{1000} = 0.45$.
(e) Probability Undergraduate-Female (UF):
- UF = 150.
- Probability = $\frac{150}{1000} = 0.15$.
(f) Probability Graduate given Female (G|F):
- Graduate Females = 250, Total females = 400.
- Probability = $\frac{250}{400} = 0.625$.
(g) Probability Male given Undergraduate (M|U):
- Male Undergraduates = 150, Total undergraduates = 300.
- Probability = $\frac{150}{300} = 0.5$.
4. **Problem 05: Produce shipper fruit conditions**
- Total boxes = 10,000.
- Ecuador boxes = 6000, Honduran boxes = 4000.
(a) Probability box has damaged fruit:
- Damaged total = 200 + 365 = 565.
- Probability = $\frac{565}{10000} = 0.0565$.
Probability box has overripe fruit:
- Overripe total = 840 + 295 = 1135.
- Probability = $\frac{1135}{10000} = 0.1135$.
(b) Probability box is from Ecuador or Honduras:
- All boxes are from either Ecuador or Honduras.
- Probability = 1.
(c) Probability box is from Honduras given it contains overripe fruit:
- Overripe from Honduras = 295.
- Overripe total = 1135.
- Probability = $\frac{295}{1135} \approx 0.2599$.
(d) Probability box has damaged or overripe fruit if mutually exclusive:
- Sum of damaged + overripe = 565 + 1135 = 1700.
- Probability = $\frac{1700}{10000} = 0.17$.
If not mutually exclusive, assume no overlap given. Thus same result of 0.17.
**Final answers:**
- Problem 02: (a) $\frac{3}{13}$, (b) $\frac{1}{13}$, (c) $\frac{1}{26}$.
- Problem 03: (a) $\frac{1}{15}$, (b) $\frac{22}{45}$, (c) $\frac{1}{4}$.
- Problem 04: (a) 0.3, (b) 0.7, (c) 0.4, (d) 0.45, (e) 0.15, (f) 0.625, (g) 0.5.
- Problem 05: (a) damaged 0.0565, overripe 0.1135, (b) 1, (c) 0.2599, (d) 0.17 if mutually exclusive or not.