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505-555 Level|   Probability|                     
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athudi1507
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Two integers will be randomly selected from the sets above, one intege 08 May 2024, 00:03
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­KarishmaB
plz explain the same question with permutation and combinaton method and plz explain the logic behind it
 
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athudi1507
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Two integers will be randomly selected from the sets above, one intege 08 May 2024, 00:35
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walker
B

\(p=\frac{C^4_1}{C^4_1*C^5_1}=\frac{4}{4*5}=0.20\)

or

\(p=\frac{4}{4}*\frac{1}{5}=0.20\)

or

\(p=\frac{4}{5}*\frac{1}{4}+\frac{1}{5}*\frac{0}{4}=0.20\)
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­can u plz explain logic behind ur first answer
thanks in adv
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KarishmaB
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Two integers will be randomly selected from the sets above, one intege 09 May 2024, 02:37
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vermatanya
A = {2, 3, 4, 5}
B = {4, 5, 6, 7, 8}

Two integers will be randomly selected from the sets above, one integer from set A and one integer from set B. What is the probability that the sum of the two integers will equal 9?


(A) 0.15
(B) 0.20
(C) 0.25
(D) 0.30
(E) 0.33
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­
Best way to solve it is to notice that you can select any number from A. There is going to be exactly one corresponding number in B which will lead to a sum of 9. 
So select any number from A. Probability = 1
Of the 5 numbers of B, exactly 1 will give you a sum of 9. So probability = 1/5


Method 2:
Total number of ways of selecting 2 numbers = 4C1 * 5C1 = 20
Favorable cases = (2, 7) (3, 6) (4, 5) and (5, 4)
Probability = 4/20 = 1/5

Answer (B)Video on Combinations: https://youtu.be/tUPJhcUxllQ
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Two integers will be randomly selected from the sets above, one intege 26 May 2025, 19:52
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