We are to show that if X ⊆ Y then (X ∪ Z) ⊆ (Y ∪ Z) for sets X, Y, Z.
Assume that a is a representative element of X, that is, a ∈ X. By the definition of union, a ∈ X ∪ Z. Now because X ⊆ Y and we assumed a ∈ X, then a ∈ Y by the definition of subset. And because a ∈ Y, then a ∈ Y ∪ Z by definition of union.
We chose our representative element, a, and showed that a ∈ X ∪ Y implies that a ∈ Y ∪ Z and this completes the proof.
Answer:
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Explanation:
The figure attached shows the <em>Venn diagram </em>for the given sets.
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<em><u>a) What is the probability that the number chosen is a multiple of 3 given that it is a factor of 24?</u></em>
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From the whole numbers 1 to 15, the multiples of 3 that are factors of 24 are in the intersection of the two sets: 3, 6, and 12.
There are a total of 7 multiples of 24, from 1 to 15.
Then, there are 3 multiples of 3 out of 7 factors of 24, and the probability that the number chosen is a multiple of 3 given that is a factor of 24 is:
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<em><u>b) What is the probability that the number chosen is a factor of 24 given that it is a multiple of 3?</u></em>
The factors of 24 that are multiples of 3 are, again, 3, 6, and 12. Thus, 3 numbers.
The multiples of 3 are 3, 6, 9, 12, and 15: 5 numbers.
Then, the probability that the number chosen is a factor of 24 given that is a multiple of 3 is:
Answer:
x = 4
Step-by-step explanation:
Using cosine triangle formula, we know that;
c² = a² + b² - 2ac(cos C)
From our diagram;
a = 2x
b = x + 1
c = 7
C = 60°
Thus;
7² = (2x)² + (x + 1)² - 2(2x)(x + 1)cos 60
49 = 4x² + (x² + 2x + 1) - (4x² + 4x)(0.5)
49 = 5x² + 2x + 1 - 2x² - 2x
3x² + 1 - 49 = 0
3x² - 48 = 0
3x² = 48
x² = 48/3
x² = 16
x = √16
x = 4
When the demand and supply curve intersect, that is, where the quantity demanded and quantity supplied are equal, the market is said to be in equilibrium. Thus, the given quantity is equilibrium quantity.
From the graph, we see that when the production cost of wheat is $4, the equilibrium quantity is 600 units.
When the production cost lowers from $4 to $3, the supply of wheat increases, such that the equilibrium quantity increases from 600 units to 800 units.
Thus, after an increase in supply, the equilibrium quantity increases.
So, Option A is the correct answer.
