حل السؤال 15، 4MA1/1H يناير 2023: المخططات الشجرية للأحداث المترابطة

1. 1The 9 cards are A, 7, H, F, E, D, G, 5, C, so 2 have numbers and 7 have letters
2. 2First card: P(number) = 2/9 and P(letter) = 7/9
3. 3Tomas keeps the first card, so only 8 cards are left for the second card
4. 4If the first card was a number: 1 number and 7 letters left, so P(number) = 1/8 and P(letter) = 7/8
5. 5If the first card was a letter: 2 numbers and 6 letters left, so P(number) = 2/8 and P(letter) = 6/8

AnswerFirst card: 2/9 number, 7/9 letter. Second card: 1/8 number and 7/8 letter after a number; 2/8 number and 6/8 letter after a letter

1. 1P(number then number) = P(first number) × P(second number | first was number)
2. 2P(first number) = 2/9
3. 3P(second number | first was number) = 1/8
4. 4(2/9) × (1/8) = 2/72
5. 52/72 = 1/36

Answer1/36

1. 1P(one number and one letter) = P(number then letter) + P(letter then number)
2. 2P(number then letter) = (2/9) × (7/8) = 14/72
3. 3P(letter then number) = (7/9) × (2/8) = 14/72
4. 4Total = 14/72 + 14/72 = 28/72
5. 528/72 = 7/18

Answer7/18