Question

If a dice is thrown 7 times, then the probability of obtaining 5 exactly 4 times is :

• A. ⁷C₄ $\left( \frac { 1 } { 6 } \right) ^ { 3 }$ $\left( \frac { 5 } { 6 } \right) ^ { 4 }$
• B. $\left( \frac { 1 } { 6 } \right) ^ { 3 }$ $\left( \frac { 5 } { 6 } \right) ^ { 4 }$
• C. ⁷C₄ $\left( \frac { 1 } { 6 } \right) ^ { 4 }$ $\left( \frac { 5 } { 6 } \right) ^ { 3 }$
• D. $\left( \frac { 1 } { 6 } \right) ^ { 4 }$ $\left( \frac { 5 } { 6 } \right) ^ { 3 }$

Answer 1

Answer: (C)

⁷C₄ $\left( \frac { 1 } { 6 } \right) ^ { 4 }$ $\left( \frac { 5 } { 6 } \right) ^ { 3 }$

Answer 2

p = $\frac { 1 } { 6 }$ ; q = $\frac { 5 } { 6 }$; n = 7

P (X = 4) ⁷C₄ p⁴ q³