Answer:
I think the answer you're looking for is -49.05
(longer version: -49.0504)
Answer:
(a) 0.4242
(b) 0.0707
Step-by-step explanation:
The total number of ways of selecting 8 herbs from 12 is

(a) If 2 herbs are selected, then there are 8 - 2 = 6 herbs to be selected from 12 - 8 = 10. The number of ways of the selection is then

Note that this is the number of ways that both are included. We would have multiplied by 2! if any of them were to be included.
The probability = 
(b) If 5 herbs are selected, then there are 8 - 5 = 3 herbs to be selected from 12 - 5 = 7. The number of ways of the selection is then

This is the number of ways that both are included. We would have multiplied by 5! if any of them were to be included. In that case, our probability will exceed 1; this implies that certainly, at least, one of them is included.
The probability = 
Answer:
4, 8, 16, 32, 64
Step-by-step explanation:
The nth term of a geometric sequence is
= a₁
Given
a₇ = 256 and a₁₀ = 2048 , then
a₁
= 256 → (1)
a₁
= 2048 → (2)
Divide (2) by (1)
= 
r³ = 8 ( take the cube root of both sides )
r =
= 2
Substitute r = 2 into (1)
a₁ ×
= 256
a₁ × 64 = 256 ( divide both sides by 64 )
a₁ = 4
Then
a₁ = 4
a₂ = 2a₁ = 2 × 4 = 8
a₃ = 2a₂ = 2 × 8 = 16
a₄ = 2a₃ = 2 × 16 = 32
a₅ = 2a₄ = 2 × 32 = 64