Total number of balls = (2 + 3 + 2) = 7.
Let S be the sample space.
| Then, n(S) |
= Number of ways of drawing 2 balls out of 7 |
|
= 7C2 ` |
|
|
|
= 21. |
Let E = Event of drawing 2 balls, none of which is blue.
| ∴ n(E) |
= Number of ways of drawing 2 balls out of (2 + 3) balls. |
|
= 5C2 |
|
|
|
= 10. |
| ∴ P(E) = |
n(E) |
= |
10 |
. |
| n(S) |
21 |
