Answer:
1. 0.0014
2. 0.0083
Step-by-step explanation:
1. The probability of selecting Birch out of 10 options is 1/10
The probability of selecting Pine out of other 9 options is 1/9
The probability of selecting Willow out of other 8 options is 1/8
The total probability of selection Birch, Pine and Willow in that order is
1/10 * 1/9 * 1/8 = 1/720 = 0.0014
2. When order is disregarded, then:
The probability of selecting any one of Ash, Birch and Spruce out of 10 options is 3/10
The probability of selecting any one of the other 2 out of 9 options is 2/9
The probability of selecting the last one out of the last 8 options is 1/8
So the total probability of selecting Ash, Birch, and Spruce, without regard to order is
3/10 * 2/9 * 1/8 = 6/720 = 1/120 = 0.0083