Answer:
7.9km
Step-by-step explanation:
(a)See attached for the diagram representing this situation.
(b)
In Triangle ABC
Next, we determine the value of Angle B.
Finally, we find b.
The distance between the small plane and the observation tower is 7.9km.
Answer:
1,968
Step-by-step explanation:
Let x₁ and x₂, y₁ and y₂, and z₁ and z₂ represent the 3 pairs of siblings, and let;
Set X represent the set where the siblings x₁ and x₂ sit together
Set Y represent the set where the siblings y₁ and y₂ sit together
Set Z represent the set where the siblings z₁ and z₂ sit together
We have;
Where the three siblings don't sit together given as ∩
∩
By set theory, we have;
=
=
=
Therefore;
Where;
= The number of ways the 3 pairs of siblings can sit on the 7 chairs = 7!
= The number of ways x₁ and x₂ can sit together on the 7 chairs = 2 × 6!
= The number of ways y₁ and y₂ can sit together on the 7 chairs = 2 × 6!
= The number of ways z₁ and z₂ can sit together on the 7 chairs = 2 × 6!
= The number of ways x₁ and x₂ and y₁ and y₂ can sit together on the 7 chairs = 2 × 2 × 5!
= The number of ways x₁ and x₂ and z₁ and z₂ can sit together on the 7 chairs = 2 × 2 × 5!
= The number of ways y₁ and y₂ and z₁ and z₂ can sit together on the 7 chairs = 2 × 2 × 5!
= The number of ways x₁ and x₂, y₁ and y₂ and z₁ and z₂ can sit together on the 7 chairs = 2 × 2 × 2 × 4!
Therefore, we get;
= 7! - (2×6! + 2×6! + 2×6! - 2 × 2 × 5! - 2 × 2 × 5! - 2 × 2 × 5! + 2 × 2 × 2 × 4!)
= 5,040 - 3072 = 1,968
The number of ways where the three siblings don't sit together given as = 1,968