Chapter 2, Problem 1E

Program Description Answer

A number is an abstract mathematical unit which is subjected to the laws of arithmetic.

Hence, the correct option is “A”.

Explanation of Solution

Number:

• A number is actually a mathematical object used for counting, labeling and measuring.
• There are many types of numbers such as
  • Natural numbers
  • Whole numbers
  • Negative numbers
  • Rational numbers
  • Irrational numbers
  • Positive numbers
• Numbers are mainly used for arithmetic operations such as addition, subtraction, multiplication, division and so on.
• The study of properties of number is known as number theory.

Explanation for incorrect options:

b. Natural number:

A natural number is a type of number. Natural numbers are positive integers or whole numbers such as 1, 2, 3 and so on and sometimes 0 as well.

Hence, the option “B” is wrong.

c. Integer number:

An integer number is also a type of number. It is a whole number that can be positive, negative or zero.

Hence, the option “C” is wrong.

d. Negative number:

A negative number is also a type of number. It is a real number which is less than zero.

Hence, the option “D” is wrong.

e. Rational number:

Rational number is also a type of number. It is any number that can be expressed as fraction or as a quotient.

Hence, the option “E” is wrong