Question

A person tosses a die unit 6 turns up. Then the probability that he throws 6 before throwing 2 or 3 is

• A. ½
• B. ¼
• C. 1/3
• D. 2/3

Answer 1

Answer: (C)

1/3

Answer 2

P(5) = P₁ + P₂ + P₃ ......... ∞

= $\frac { 1 } { 6 } + \frac { 1 } { 2 } \times \frac { 1 } { 6 } + \left( \frac { 1 } { 2 } \right) ^ { 2 } \cdot \frac { 1 } { 6 } + \ldots \ldots \ldots$

P(5) = $\frac { \frac { 1 } { 6 } } { 1 - \frac { 1 } { 2 } } = \frac { 1 } { 3 }$ .