Question

The probability of getting a sum of at least 6 in three throws of a coin is

• A. 119/216
• B. 103/108
• C. 50/53
• D. None

Answer 1

Answer: (B)

103/108

Answer 2

Le E be the event of getting a sum of 6 or more

∴ $\overline { \mathrm { E } }$ = {(1, 1, 1), (1, 1, 2), (1, 2, 1), (2, 1, 1), (1, 2, 2), (2, 1, 2), (2, 2, 1), (1, 1, 3),(1,3,1), (3,1,1)}

n($\overline { \mathrm { E } }$) = 10

∴ P(5) = 1 -