A die is rolled five times and a 5 or 6 is considered a success. Find the probability of
(i) at least 2 successes,
(ii) at least one but no more than 3 successes.

Respuesta :

Answer:

(i) The probability of at least 2 successes is 0.2093.

(ii) The probability of at least one but no more than 3 successes is 0.9548.

Step-by-step explanation:

Now the total number of cases = {1, 2, 3, 4, 5, 6} = 6.

Favourable cases = {1, 6} = 2.

[tex]p = \frac{2} {3} = \frac{1} {3} \\\\q = 1- p\\\\q = \frac{2}{3} \\\\n=5[/tex]

i) at least 2 successes,

[tex]P(X\geq 2) = (^{n}C_{x} )\times p^{x} \times (1-p)^{n-x}\\\\P(X\geq 2) = 0.2093[/tex]

ii) at least one but no more than 3 successes,

[tex]P(X\leq 3) = (^{n}C_{x} )\times p^{x} \times (1-p)^{n-x}\\\\P(X\leq 3)= 0.9548[/tex]