The number of trays that contain both a cup and a plate = 11.
<h3>What are sets?</h3>
A set is the mathematical model for a collection of different things; a set contains elements or members, which can be mathematical objects of any kind
To find the elements in the sets A and B, we refer to the formula:
n(A) + n(B) - n(A∪B) = n(A∩B),
where,
- n(A) = number of elements in set A,
- n(B) = number of elements in set B,
- n(A∪B) = number of elements that are either in set A or B,
- n(A∩B) = number of elements that are in both the sets A and B.
Given:
- Number of trays on a table: 25
- Each tray has either:
- only a cup
- only a plate
- both cup and plate
- Trays containing cups = 15
- Trays containing plates = 21
To find: number of trays containing both cup and plate.
Finding:
Let the number of trays containing cups be C and those containing plate be P.
Then, n(C) = number of tray containing only cups = 15
n(P) = number of tray containing only plates = 21
n(C∩P) = ?
Since, each plate contains at least a cup or a plate, n(U) = total number of trays = n(C∪P) = number of trays containing either a cup or a plate
=> n(C∪P) = 25
By the formula of sets: n(A) + n(B) - n(A∪B) = n(A∩B),
We get: n(C∩P) = 15 + 21 - 25 = 15 - 4 = 11
Hence, the number of trays that contain both a cup and a plate = 11.
To learn more about sets, refer to the link: brainly.com/question/13458417
#SPJ4
Answer:
Statement 3
Step-by-step explanation:
<u>Statement 1:</u> For any positive integer n, the square root of n is irrational.
Suppose n = 25 (25 is positive integer), then
Since 5 is rational number, this statement is false.
<u>Statement 2:</u> If n is a positive integer, the square root of n is rational.
Suppose n = 8 (8 is positive integer), then
Since is irrational number, this statement is false.
<u>Statement 3:</u> If n is a positive integer, the square root of n is rational if and only if n is a perfect square.
If n is a positive integer and square root of n is rational, then n is a perfect square.
If n is a positive integer and n is a perfect square, then square root of n is a rational number.
This statement is true.
Answer:
89 over 5
Step-by-step explanation:
Answer:
1/8 is at the bank, 1/4 at the mall and 5/8 at the library
Step-by-step explanation: