Question:
A dice is thrown 3 times. What is the probability that the sum of numbers is exactly 7?
एक पासा 3 बार फेंका जाता है। संख्याओं का योग ठीक 7 आने की संभावना क्या है?
Options:
- a) 15/216
- b) 15/108
- c) 5/72
- d) 1/36
- a) 15/216
- b) 15/108
- c) 5/72
- d) 1/36
correct answer : a)
Explanation:
Total outcomes = 6^3 = 216. Favorable outcomes for sum=7: (1,1,5),(1,5,1),(5,1,1),(1,2,4),(1,4,2),(2,1,4),(2,4,1),(4,1,2),(4,2,1),(2,2,3),(2,3,2),(3,2,2),(1,3,3),(3,1,3),(3,3,1) = 15 outcomes. P = 15/216.
कुल = 216। अनुकूल = 15 (योग=7 वाले संयोजन)। P = 15/216।