1.
Which of these numbers is not polite?
Correct Answer
A. 3
Explanation
In this question, the numbers 3, 6, 9, and 12 are given as options. Polite numbers are those that can be divided by 3 without leaving a remainder. When we divide 3 by 3, it leaves no remainder, making it a polite number. Therefore, the correct answer is 3 because it is the only number in the given options that is polite.
2.
Which of these is the other name for polite numbers?
Correct Answer
A. Trapezoidal number
Explanation
Trapezoidal numbers are a sequence of numbers that can be represented as the sum of consecutive integers. They are also known as polite numbers because they can be expressed as the sum of two or more consecutive positive integers in a "polite" or respectful way. For example, 6 can be expressed as 1+2+3, which is a polite way of representing it. Therefore, the other name for polite numbers is Trapezoidal numbers.
3.
How are police numbers described in the American context?
Correct Answer
B. Staircase numbers
4.
What is the politeness of 9?
Correct Answer
D. 2
5.
What is the politeness of 15?
Correct Answer
D. 3
Explanation
The question is asking for the politeness of the number 15. In mathematics, politeness refers to the number of ways a number can be expressed as the sum of consecutive positive integers. To determine the politeness of 15, we need to find the number of ways it can be expressed as the sum of consecutive positive integers. The only way to do this is by adding 7 and 8 together. Therefore, the politeness of 15 is 3.
6.
How is the politeness of numbers obtained?
Correct Answer
C. Through its odd divisors
Explanation
The politeness of a number is obtained through its odd divisors. This means that the number can be expressed as the sum of consecutive odd numbers. For example, the number 9 can be expressed as 2 + 3 + 4, where 2, 3, and 4 are consecutive odd numbers. Therefore, the politeness of 9 is 3.
7.
What is the politeness of 90?
Correct Answer
C. 5
8.
What kind of numbers is more polite?
Correct Answer
A. Odd numbers
Explanation
Odd numbers are considered more polite because they can be evenly divided into pairs, leaving no remainder. This symmetry and balance in division is seen as polite and considerate. In contrast, even numbers cannot be divided into pairs without a remainder, which is seen as less polite. Therefore, odd numbers are considered to be more polite than even numbers.
9.
What kind of diagram best describes politeness of numbers?
Correct Answer
C. Young diagram
Explanation
A Young diagram is a type of diagram that best describes the politeness of numbers. It is a graphical representation of a partition of a positive integer, where the numbers are arranged in rows and columns such that each row has a non-decreasing sequence of numbers. This diagram visually represents the concept of politeness of numbers, which is the number of ways a positive integer can be expressed as the sum of consecutive positive integers. Therefore, a Young diagram is the most suitable diagram to depict this concept.
10.
Which of these is the best indicator of the politeness of a number?
Correct Answer
C. Prime factors
Explanation
Prime factors are the best indicator of the politeness of a number because they represent the unique prime numbers that divide the number evenly. The presence of prime factors indicates that the number can be expressed as a product of prime numbers, which suggests that it has a greater number of factors and is therefore considered more polite. Even factors, odd factors, and highest common factors do not provide the same level of information about the number's factors and do not necessarily indicate its politeness.